Freescale Semiconductor MPC850 User manual

MPC850UM/D
Rev. 1, 1/2001
MPC850 Family User’s Manual
Integrated Communications Microprocessor
Supports MPC850
MPC850DE
MPC850SR
MPC850DSL
Freescale Semiconductor
Freescale Semiconductor
© Freescale Semiconductor, Inc., 2004. All rights reserved.

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I
IV
IND
Part I—Overview
MPC850 Overview
Memory Map
Part II—PowerPC Microprocessor Module
PowerPC Core
PowerPC Core Register Set
MPC850 Instruction Set
Exceptions
Instruction and Data Caches
Memory Management Unit
Instruction Execution Timing
Part III—PowerPC Microprocessor Module
System Interface Unit
Reset
Part IV—Hardware Interface
External Signals
External Bus Interface
Clocks and Power Control
Memory Controller
PCMCIA Interface

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IV
Part I—Overview
MPC850 Overview
Memory Map
Part II—PowerPC Microprocessor Module
PowerPC Core
PowerPC Core Register Set
MPC850 Instruction Set
Exceptions
Instruction and Data Caches
Memory Management Unit
Instruction Execution Timing
Part III—PowerPC Microprocessor Module
System Interface Unit
Reset
Part IV—Hardware Interface
External Signals
External Bus Interface
Clocks and Power Control
Memory Controller
PCMCIA Interface

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Part V—Communications Processor Module
Communications Processor Module and Timers
Communications Processor
SDMA Channels and IDMA Emulation
Serial Interface
SCC Introduction
SCC UART Mode
SCC HDLC Mode
SCC AppleTalk Mode
SCC Asynchronous HDLC Mode and IrDA
SCC BISYNC Mode
SCC Ethernet Mode
SCC Transparent Mode
IrDA Mode—SCC2 Only
Serial Management Controllers
Serial Peripheral Interface
Universal Serial Bus Controller
I
2
C Controller
Parallel I/O Ports
CPM Interrupt Controller
Part VI—Asynchronous Transfer Mode
ATM Overview
Buffer Descriptors and Connection Tables
ATM Parameter RAM
ATM Controller
ATM Pace Control
ATM Exceptions
Interface Configuration
UTOPIA Interface
Part VII—System Debugging and Testing Support
System Development and Debugging
IEEE 1149.1 Test Access Port
Byte Ordering
Serial Communication Performance
Register Quick Reference Guide
Instruction Set Listings
MPC850
MPC850DSL
Glossary
Index

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Part V—Communications Processor Module
Communications Processor Module and Timers
Communications Processor
SDMA Channels and IDMA Emulation
Serial Interface
SCC Introduction
SCC UART Mode
SCC HDLC Mode
SCC AppleTalk Mode
SCC Asynchronous HDLC Mode and IrDA
SCC BISYNC Mode
SCC Ethernet Mode
SCC Transparent Mode
IrDA Mode—SCC2 Only
Serial Management Controllers
Serial Peripheral Interface
Universal Serial Bus Controller
I2C Controller
Parallel I/O Ports
CPM Interrupt Controller
Part VI—Asynchronous Transfer Mode
ATM Overview
Buffer Descriptors and Connection Tables
ATM Parameter RAM
ATM Controller
ATM Pace Controller
ATM Exceptions
Interface Configuration
UTOPIA Interface
MPC850DSL
Part VII—System Debugging and Testing Support
System Development and Debugging
IEEE 1149.1 Test Access Port
Byte Ordering
Serial Communication Performance
Register Quick Reference Guide
Instruction Set Listings
MPC850
Glossary
Index

CONTENTS
Paragraph
Number Title Page
Number
Contents vii
Part I
Overview
Chapter 1
Overview
1.1 Features............................................................................................................... 1–2
1.2 Overview of Major Components ........................................................................ 1–7
1.2.1 PowerPC Microprocessor Module.................................................................. 1–8
1.2.2 Configuration and Reset ................................................................................. 1–8
1.2.2.1 System Interface Unit (SIU) ....................................................................... 1–8
1.2.2.2 Resets.......................................................................................................... 1–9
1.2.3 MPC850 Hardware Interface ........................................................................ 1–10
1.2.3.1 Signals....................................................................................................... 1–11
1.2.3.2 Clocking and Power Management............................................................ 1–13
1.2.3.3 Memory Controller ................................................................................... 1–14
1.2.4 Communications Processor Module (CPM) ................................................. 1–15
1.2.5 System Debugging and Testing Support ...................................................... 1–17
1.3 Differences between the MPC850 Family and MPC860.................................. 1–17
Chapter 2
Memory Map
Part II
PowerPC Microprocessor Module
Chapter 3
The PowerPC Core
3.1 The MPC850 Core as a PowerPC Implementation............................................. 3-1
3.2 PowerPC Architecture Overview........................................................................ 3-1
3.2.1 Levels of the PowerPC Architecture .............................................................. 3-3
3.3 Features............................................................................................................... 3-4
3.4 Basic Structure of the Core ................................................................................. 3-5
3.4.1 Instruction Flow.............................................................................................. 3-6
3.4.2 Basic Instruction Pipeline ............................................................................... 3-7
3.4.3 Instruction Unit ............................................................................................... 3-7
3.4.3.1 Branch Operations ...................................................................................... 3-7
3.4.3.2 Dispatching Instructions ............................................................................. 3-9
3.5 Register Set ......................................................................................................... 3-9
3.6 Execution Units................................................................................................... 3-9

MPC850 Family User’s Manual
CONTENTS
Paragraph
Number Title Page
Number
3.6.1 Branch Processing Unit ................................................................................ 3-10
3.6.2 Integer Unit ................................................................................................... 3-10
3.6.3 Load/Store Unit............................................................................................. 3-10
3.6.3.1 Executing Load/Store Instructions ........................................................... 3-12
3.6.3.2 Serializing Load/Store Instructions .......................................................... 3-12
3.6.3.3 Store Accesses .......................................................................................... 3-12
3.6.3.4 Nonspeculative Load Instructions ............................................................ 3-13
3.6.3.5 Unaligned Accesses .................................................................................. 3-13
3.6.3.6 Atomic Update Primitives ........................................................................ 3-14
3.7 The MPC850 and the PowerPC Architecture ................................................... 3-14
Chapter 4
PowerPC Core Register Set
4.1 MPC850 Register Implementation ..................................................................... 4-1
4.1.1 PowerPC Registers—User Registers .............................................................. 4-2
4.1.1.1 PowerPC User-Level Register Bit Assignments ........................................ 4-2
4.1.1.1.1 Condition Register (CR)......................................................................... 4-2
4.1.1.1.2 Condition Register CR0 Field Definition............................................... 4-3
4.1.1.1.3 XER ........................................................................................................ 4-3
4.1.1.1.4 Time Base Registers ............................................................................... 4-4
4.1.2 PowerPC Registers—Supervisor Registers .................................................... 4-4
4.1.2.1 DAR, DSISR, and BAR Operation............................................................. 4-5
4.1.2.2 Unsupported Registers................................................................................ 4-6
4.1.2.3 PowerPC Supervisor-Level Register Bit Assignments............................... 4-6
4.1.2.3.1 Machine State Register (MSR)............................................................... 4-6
4.1.2.3.2 Processor Version Register..................................................................... 4-8
4.1.3 MPC850-Specific SPRs.................................................................................. 4-8
4.1.3.1 Accessing SPRs ........................................................................................ 4-11
4.2 Register Initialization at Reset .......................................................................... 4-11
Chapter 5
MPC850 Instruction Set
5.1 Operand Conventions.......................................................................................... 5-1
5.1.1 Data Organization in Memory and Data Transfers......................................... 5-1
5.1.2 Aligned and Misaligned Accesses .................................................................. 5-1
5.2 Instruction Set Summary..................................................................................... 5-2
5.2.1 Classes of Instructions .................................................................................... 5-3
5.2.1.1 Definition of Boundedly Undefined ........................................................... 5-4
5.2.1.2 Defined Instruction Class ........................................................................... 5-4
5.2.1.3 Illegal Instruction Class .............................................................................. 5-4

CONTENTS
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Number
Contents ix
5.2.1.4 Reserved Instruction Class ......................................................................... 5-5
5.2.2 Addressing Modes .......................................................................................... 5-5
5.2.2.1 Memory Addressing ................................................................................... 5-5
5.2.2.2 Effective Address Calculation .................................................................... 5-6
5.2.2.3 Synchronization .......................................................................................... 5-6
5.2.2.3.1 Context Synchronization ........................................................................ 5-6
5.2.2.3.2 Execution Synchronization..................................................................... 5-7
5.2.2.3.3 Instruction-Related Exceptions............................................................... 5-7
5.2.3 Instruction Set Overview ................................................................................ 5-7
5.2.4 PowerPC UISA Instructions ........................................................................... 5-8
5.2.4.1 Integer Instructions ..................................................................................... 5-8
5.2.4.1.1 Integer Arithmetic Instructions............................................................... 5-8
5.2.4.1.2 Integer Compare Instructions ................................................................. 5-9
5.2.4.1.3 Integer Logical Instructions.................................................................. 5-10
5.2.4.1.4 Integer Rotate and Shift Instructions .................................................... 5-10
5.2.4.2 Load and Store Instructions ...................................................................... 5-11
5.2.4.2.1 Integer Load and Store Address Generation......................................... 5-11
5.2.4.2.2 Register Indirect Integer Load Instructions .......................................... 5-12
5.2.4.2.3 Integer Store Instructions...................................................................... 5-12
5.2.4.2.4 Integer Load and Store with Byte-Reverse Instructions....................... 5-13
5.2.4.2.5 Integer Load and Store Multiple Instructions....................................... 5-13
5.2.4.2.6 Integer Load and Store String Instructions........................................... 5-14
5.2.4.3 Branch and Flow Control Instructions...................................................... 5-14
5.2.4.3.1 Branch Instruction Address Calculation............................................... 5-15
5.2.4.3.2 Branch Instructions............................................................................... 5-15
5.2.4.3.3 Condition Register Logical Instructions............................................... 5-16
5.2.4.4 Trap Instructions....................................................................................... 5-16
5.2.4.5 Processor Control Instructions.................................................................. 5-17
5.2.4.5.1 Move to/from Condition Register Instructions..................................... 5-17
5.2.4.6 Memory Synchronization Instructions—UISA ........................................ 5-17
5.2.5 PowerPC VEA Instructions .......................................................................... 5-19
5.2.5.1 Processor Control Instructions.................................................................. 5-19
5.2.5.2 Memory Synchronization Instructions—VEA ......................................... 5-20
5.2.5.2.1 eieio Behavior....................................................................................... 5-20
5.2.5.2.2 isync Behavior ...................................................................................... 5-20
5.2.5.3 Memory Control Instructions—VEA ....................................................... 5-21
5.2.6 PowerPC OEA Instructions .......................................................................... 5-21
5.2.6.1 System Linkage Instructions..................................................................... 5-22
5.2.6.2 Processor Control Instructions—OEA ..................................................... 5-22
5.2.6.2.1 Move to/from Machine State Register Instructions.............................. 5-22
5.2.6.2.2 Move to/from Special-Purpose Register Instructions........................... 5-22
5.2.6.3 Memory Control Instructions—OEA ....................................................... 5-23

MPC850 Family User’s Manual
CONTENTS
Paragraph
Number Title Page
Number
Chapter 6
Exceptions
6.1 Exceptions........................................................................................................... 6-2
6.1.1 Exception Ordering......................................................................................... 6-3
6.1.2 PowerPC-Defined Exceptions ........................................................................ 6-4
6.1.2.1 System Reset Interrupt (0x00100) .............................................................. 6-5
6.1.2.2 Machine Check Interrupt (0x00200) .......................................................... 6-5
6.1.2.3 DSI Exception (0x00300) ........................................................................... 6-6
6.1.2.4 ISI Exception (0x00400)............................................................................. 6-6
6.1.2.5 External Interrupt Exception (0x00500)..................................................... 6-6
6.1.2.6 Alignment Exception (0x00600) ................................................................ 6-7
6.1.2.6.1 Integer Alignment Exceptions ................................................................ 6-8
6.1.2.7 Program Exception (0x00700).................................................................... 6-9
6.1.2.8 Decrementer Exception (0x00900)........................................................... 6-10
6.1.2.9 System Call Exception (0x00C00) ........................................................... 6-10
6.1.2.10 Trace Exception (0x00D00) ..................................................................... 6-11
6.1.2.11 Floating-Point Assist Exception ............................................................... 6-12
6.1.3 Implementation-Specific Exceptions............................................................ 6-12
6.1.3.1 Software Emulation Exception (0x01000) ............................................... 6-12
6.1.3.2 Instruction TLB Miss Exception (0x01100)............................................. 6-12
6.1.3.3 Data TLB Miss Exception (0x01200)....................................................... 6-13
6.1.3.4 Instruction TLB Error Exception (0x01300) ............................................ 6-13
6.1.3.5 Data TLB Error Exception (0x014000).................................................... 6-14
6.1.3.6 Debug Exceptions (0x01C00–0x01F00) .................................................. 6-15
6.1.4 Implementing the Precise Exception Model................................................. 6-16
6.1.5 Recoverability after an Exception................................................................. 6-17
6.1.6 Exception Latency ........................................................................................ 6-18
6.1.7 Partially Completed Instructions .................................................................. 6-20
Chapter 7
Instruction and Data Caches
7.1 Instruction Cache Organization .......................................................................... 7–2
7.2 Data Cache Organization .................................................................................... 7–4
7.3 Cache Control Registers ..................................................................................... 7–6
7.3.1 Instruction Cache Control Registers ............................................................... 7–6
7.3.1.1 Reading Data and Tags in the Instruction Cache........................................ 7–8
7.3.1.2 IC_CST Commands.................................................................................... 7–9
7.3.1.2.1 Instruction Cache Enable/Disable Commands ....................................... 7–9
7.3.1.2.2 Instruction Cache Load & Lock Cache Block Command ...................... 7–9
7.3.1.2.3 Instruction Cache Unlock Cache Block Command.............................. 7–10

CONTENTS
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Contents xi
7.3.1.2.4 Instruction Cache Unlock All Command ............................................. 7–11
7.3.1.2.5 Instruction Cache Invalidate All Command ......................................... 7–11
7.3.2 Data Cache Control Registers....................................................................... 7–11
7.3.2.1 Reading Data Cache Tags and Copyback Buffer ..................................... 7–14
7.3.2.2 DC_CST Commands ................................................................................ 7–15
7.3.2.2.1 Data Cache Enable/Disable Commands ............................................... 7–16
7.3.2.2.2 Data Cache Load & Lock Cache Block Command.............................. 7–16
7.3.2.2.3 Data Cache Unlock Cache Block Command........................................ 7–17
7.3.2.2.4 Data Cache Unlock All Command ....................................................... 7–17
7.3.2.2.5 Data Cache Invalidate All Command................................................... 7–17
7.3.2.2.6 Data Cache Flush Cache Block Command........................................... 7–17
7.4 PowerPC Cache Control Instructions ............................................................... 7–18
7.4.1 Instruction Cache Block Invalidate (
icbi )..................................................... 7–18
7.4.2 Data Cache Block Touch (
dcbt ) and Data Cache Block
Touch for Store (
dcbtst ) ...........................................................................7–18
7.4.3 Data Cache Block Zero (
dcbz ) ..................................................................... 7–19
7.4.4 Data Cache Block Store (
dcbst ) ................................................................... 7–19
7.4.5 Data Cache Block Flush (
dcbf ) .................................................................... 7–20
7.4.6 Data Cache Block Invalidate (
dcbi ) ............................................................. 7–20
7.5 Instruction Cache Operations............................................................................ 7–20
7.5.1 Instruction Cache Hit .................................................................................... 7–22
7.5.2 Instruction Cache Miss ................................................................................. 7–22
7.5.3 Instruction Fetching on a Predicted Path ...................................................... 7–23
7.5.4 Fetching Instructions from Caching-Inhibited Regions................................ 7–23
7.5.5 Updating Code and Memory Region Attributes ........................................... 7–24
7.6 Data Cache Operation ....................................................................................... 7–24
7.6.1 Data Cache Load Hit..................................................................................... 7–25
7.6.2 Data Cache Read Miss.................................................................................. 7–25
7.6.3 Write-Through Mode.................................................................................... 7–26
7.6.3.1 Data Cache Store Hit in Write-Through Mode......................................... 7–26
7.6.3.2 Data Cache Store Miss in Write-Through Mode...................................... 7–26
7.6.4 Write-Back Mode ......................................................................................... 7–26
7.6.4.1 Data Cache Store Hit in Write-Back Mode .............................................. 7–26
7.6.4.2 Data Cache Store Miss in Write-Back Mode ........................................... 7–27
7.6.5 Data Accesses to Caching-Inhibited Memory Regions ................................ 7–27
7.6.6 Atomic Memory References......................................................................... 7–28
7.7 Cache Initialization after Reset......................................................................... 7–29
7.8 Debug Support .................................................................................................. 7–29
7.8.1 Instruction and Data Cache Operation in Debug Mode................................ 7–30
7.8.2 Instruction and Data Cache Operation with a Software Monitor Debugger. 7–30

MPC850 Family User’s Manual
CONTENTS
Paragraph
Number Title Page
Number
Chapter 8
Memory Management Unit
8.1 Features............................................................................................................... 8–1
8.2 PowerPC Architecture Compliance .................................................................... 8–2
8.3 Address Translation ............................................................................................ 8–3
8.3.1 Translation Disabled ....................................................................................... 8–3
8.3.2 Translation Enabled ........................................................................................ 8–3
8.3.3 TLB Operation................................................................................................ 8–5
8.4 Using Access Protection Groups ........................................................................ 8–6
8.5 Protection Resolution Modes.............................................................................. 8–7
8.6 Memory Attributes.............................................................................................. 8–8
8.7 Translation Table Structure................................................................................. 8–9
8.7.1 Level-One Descriptor ................................................................................... 8–12
8.7.2 Level-Two Descriptor................................................................................... 8–13
8.7.3 Page Size....................................................................................................... 8–14
8.8 Programming Model ......................................................................................... 8–14
8.8.1 IMMU Control Register (MI_CTR) ............................................................. 8–15
8.8.2 DMMU Control Register (MD_CTR) .......................................................... 8–16
8.8.3 IMMU/DMMU Effective Page Number Register (Mx_EPN) ..................... 8–17
8.8.4 IMMU Tablewalk Control Register (MI_TWC) .......................................... 8–18
8.8.5 DMMU Tablewalk Control Register (MD_TWC) ....................................... 8–19
8.8.6 IMMU Real Page Number Register (MI_RPN) ........................................... 8–20
8.8.7 DMMU Real Page Number Register (MD_RPN) ........................................ 8–21
8.8.8 MMU Tablewalk Base Register (M_TWB) ................................................. 8–23
8.8.9 MMU Current Address Space ID Register (M_CASID).............................. 8–23
8.8.10 MMU Access Protection Registers (MI_AP/MD_AP) ................................ 8–24
8.8.11 MMU Tablewalk Special Register (M_TW) ................................................ 8–24
8.8.12 MMU Debug Registers................................................................................. 8–24
8.8.12.1 IMMU CAM Entry Read Register (MI_CAM)........................................ 8–25
8.8.12.2 IMMU RAM Entry Read Register 0 (MI_RAM0)................................... 8–26
8.8.12.3 IMMU RAM Entry Read Register 1 (MI_RAM1)................................... 8–27
8.8.12.4 DMMU CAM Entry Read Register (MD_CAM)..................................... 8–27
8.8.12.5 DMMU RAM Entry Read Register 0 (MD_RAM0)................................ 8–28
8.8.13 DMMU RAM Entry Read Register 1 (MD_RAM1).................................... 8–29
8.9 Memory Management Unit Exceptions ............................................................ 8–31
8.10 TLB Manipulation ............................................................................................ 8–31
8.10.1 TLB Reload................................................................................................... 8–32
8.10.1.1 Translation Reload Examples ................................................................... 8–32
8.10.2 Locking TLB Entries .................................................................................... 8–33
8.10.3 Loading Locked TLB Entries ....................................................................... 8–34
8.10.4 TLB Invalidation........................................................................................... 8–34

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Contents xiii
Chapter 9
Instruction Execution Timing
9.1 Instruction Execution Timing Examples ............................................................ 9–1
9.1.1 Data Cache Load with a Data Dependency .................................................... 9–1
9.1.2 Writeback Arbitration ..................................................................................... 9–2
9.1.3 Private Writeback Bus Load ........................................................................... 9–3
9.1.4 Fastest External Load (Data Cache Miss)....................................................... 9–3
9.1.5 A Full Completion Queue............................................................................... 9–4
9.1.6 Branch Instruction Handling........................................................................... 9–4
9.1.7 Branch Prediction ........................................................................................... 9–5
9.2 Instruction Timing List ....................................................................................... 9–6
9.2.1 Load/Store Instruction Timing........................................................................ 9–7
9.2.2 String Instruction Latency .............................................................................. 9–8
9.2.3 Accessing Off-Core SPRs............................................................................... 9–8
Part III
Configuration and Reset
Chapter 10
System Interface Unit
10.1 Features............................................................................................................. 10–2
10.2 System Configuration and Protection ............................................................... 10–2
10.3 Multiplexing SIU Pins ...................................................................................... 10–4
10.4 Programming the SIU ....................................................................................... 10–5
10.4.1 Internal Memory Map Register (IMMR)...................................................... 10–5
10.4.2 SIU Module Configuration Register (SIUMCR).......................................... 10–6
10.4.3 System Protection Control Register (SYPCR) ............................................. 10–8
10.4.4 Transfer Error Status Register (TESR)......................................................... 10–9
10.4.5 Register Lock Mechanism .......................................................................... 10–10
10.5 System Configuration ..................................................................................... 10–11
10.5.1 Interrupt Structure....................................................................................... 10–11
10.5.2 Priority of Interrupt Sources ....................................................................... 10–13
10.5.3 SIU Interrupt Processing............................................................................. 10–14
10.5.3.1 Nonmaskable Interrupts—IRQ0 and SWT............................................. 10–14
10.5.4 Programming the SIU Interrupt Controller................................................. 10–15
10.5.4.1 SIU Interrupt Pending Register (SIPEND)............................................. 10–15
10.5.4.2 SIU Interrupt Mask Register (SIMASK)................................................ 10–17
10.5.4.3 SIU Interrupt Edge/Level Register (SIEL) ............................................. 10–18
10.5.4.4 SIU Interrupt Vector Register (SIVEC) ................................................. 10–19
10.6 The Bus Monitor............................................................................................. 10–20

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CONTENTS
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10.7 The Software Watchdog Timer....................................................................... 10–21
10.7.1 Software Service Register (SWSR) ............................................................ 10–22
10.8 The PowerPC Decrementer............................................................................. 10–23
10.8.1 Decrementer Register (DEC)...................................................................... 10–24
10.9 The PowerPC Timebase.................................................................................. 10–24
10.9.1 Timebase Register (TBU and TBL)............................................................ 10–25
10.9.2 Timebase Reference Registers (TBREFA and TBREFB).......................... 10–26
10.9.3 Timebase Status and Control Register (TBSCR) ....................................... 10–26
10.10 The Real-Time Clock...................................................................................... 10–27
10.10.1 Real-Time Clock Status and Control Register (RTCSC) ........................... 10–28
10.10.2 Real-Time Clock Register (RTC) ............................................................... 10–29
10.10.3 Real-Time Clock Alarm Register (RTCAL) .............................................. 10–29
10.10.4 Real-Time Clock Alarm Seconds Register (RTSEC)................................. 10–30
10.11 The Periodic Interrupt Timer (PIT)................................................................. 10–31
10.11.1 Periodic Interrupt Status and Control Register (PISCR) ............................ 10–32
10.11.2 PIT Count Register (PITC) ......................................................................... 10–33
10.11.3 PIT Register (PITR).................................................................................... 10–33
10.12 General SIU Timers Operation ....................................................................... 10–34
10.12.1 Freeze Operation......................................................................................... 10–34
10.12.2 Low-Power Stop Operation ........................................................................ 10–34
Chapter 11
Reset
11.1 Types of Reset................................................................................................... 11–1
11.1.1 Power-On Reset ............................................................................................ 11–2
11.1.2 External Hard Reset ...................................................................................... 11–2
11.1.3 Internal Hard Reset ....................................................................................... 11–2
11.1.3.1 PLL Loss of Lock ..................................................................................... 11–3
11.1.3.2 Software Watchdog Reset......................................................................... 11–3
11.1.3.3 Checkstop Reset........................................................................................ 11–3
11.1.4 Debug Port Hard or Soft Reset ..................................................................... 11–3
11.1.5 JTAG Reset................................................................................................... 11–3
11.1.6 Power-On and Hard Reset Sequence ............................................................ 11–4
11.1.7 External Soft Reset ....................................................................................... 11–4
11.1.8 Internal Soft Reset ........................................................................................ 11–4
11.1.9 Soft Reset Sequence...................................................................................... 11–5
11.2 Reset Status Register (RSR) ............................................................................. 11–5
11.3 MPC850 Reset Configuration........................................................................... 11–6
11.3.1 Hard Reset..................................................................................................... 11–7
11.3.1.1 Hard Reset Configuration Word............................................................... 11–9
11.3.2 Soft Reset.................................................................................................... 11–11
11.4 TRST and Power Mode Considerations ......................................................... 11–11

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Contents xv
Part IV
The Hardware Interface
Chapter 12
External Signals
12.1 System Bus Signals........................................................................................... 12–5
12.2 Active Pull-Up Buffers ................................................................................... 12–18
12.3 Internal Pull-Up and Pull-Down Resistors .................................................... 12–19
12.4 Recommended Basic Pin Connections ........................................................... 12–20
12.4.1 Reset Configuration .................................................................................... 12–20
12.4.1.1 Bus Control Signals and Interrupts......................................................... 12–20
12.4.2 JTAG and Debug Ports ............................................................................... 12–21
12.4.3 Unused Inputs ............................................................................................. 12–21
12.4.4 Unused Outputs........................................................................................... 12–21
12.5 Signal States during Hardware Reset.............................................................. 12–21
Chapter 13
External Bus Interface
13.1 Features............................................................................................................. 13–1
13.2 Bus Transfer Overview ..................................................................................... 13–1
13.3 Bus Interface Signal Descriptions..................................................................... 13–2
13.4 Bus Operations.................................................................................................. 13–6
13.4.1 Basic Transfer Protocol ................................................................................ 13–6
13.4.2 Single-Beat Transfer ..................................................................................... 13–6
13.4.2.1 Single-Beat Read Flow ............................................................................. 13–7
13.4.2.2 Single-Beat Write Flow .......................................................................... 13–10
13.4.3 Burst Transfers............................................................................................ 13–13
13.4.4 Burst Operations ......................................................................................... 13–14
13.4.5 Alignment and Data Packing on Transfers ................................................. 13–23
13.4.6 Arbitration Phase ........................................................................................ 13–26
13.4.6.1 Bus Request (BR) ................................................................................... 13–27
13.4.6.2 Bus Grant (BG)....................................................................................... 13–27
13.4.6.3 Bus Busy (BB)........................................................................................ 13–28
13.4.6.4 External Bus Parking .............................................................................. 13–30
13.4.7 Address Transfer Phase-Related Signals .................................................... 13–30
13.4.7.1 Transfer Start (TS).................................................................................. 13–30
13.4.7.2 Address Bus ............................................................................................ 13–31
13.4.7.3 Transfer Attributes.................................................................................. 13–31
13.4.7.3.1 Read/Write (RD/WR) ......................................................................... 13–31
13.4.7.3.2 Burst Indicator (BURST).................................................................... 13–31

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13.4.7.3.3 Transfer Size (TSIZ)........................................................................... 13–31
13.4.7.3.4 Address Types (AT) ........................................................................... 13–31
13.4.7.3.5 Burst Data in Progress (BDIP) ........................................................... 13–34
13.4.8 Termination Signals.................................................................................... 13–34
13.4.8.1 Transfer Acknowledge (TA)................................................................... 13–34
13.4.8.2 Burst Inhibit (BI) .................................................................................... 13–34
13.4.8.3 Transfer Error Acknowledge (TEA)....................................................... 13–34
13.4.8.4 Termination Signals Protocol ................................................................. 13–34
13.4.9 Memory Reservation................................................................................... 13–35
13.4.9.1 Kill Reservation (KR)............................................................................. 13–36
13.4.10 Bus Exception Control Cycles.................................................................... 13–37
13.4.10.1 RETRY ................................................................................................... 13–38
Chapter 14
Clocks and Power Control
14.1 Features............................................................................................................. 14–1
14.2 The Clock Module ............................................................................................ 14–2
14.2.1 External Reference Clocks............................................................................ 14–3
14.2.1.1 Off-Chip Oscillator Input (EXTCLK) ...................................................... 14–4
14.2.1.2 Crystal Oscillator Support (EXTAL and XTAL) ..................................... 14–4
14.2.2 System PLL................................................................................................... 14–5
14.2.2.1 SPLL Reset Configuration........................................................................ 14–6
14.2.2.2 SPLL Output Characteristics and Stability............................................... 14–7
14.2.2.3 The System Phase-Locked Loop Pins (VDDSYN, VSSSYN,
VSSSYN1, XFC) ..................................................................................14–7
14.2.2.4 Disabling the SPLL................................................................................... 14–8
14.3 Clock Signals .................................................................................................... 14–8
14.3.1 Clocks Derived from the SPLL Output ........................................................ 14–9
14.3.1.1 The Internal General System Clocks (GCLK1C, GCLK2C,
GCLK1, GCLK2) ...............................................................................14–10
14.3.1.2 Memory Controller and External Bus Clocks (GCLK1_50,
GCLK2_50, CLKOUT) ......................................................................14–11
14.3.1.3 CLKOUT Special Considerations: 1:2:1 Mode...................................... 14–14
14.3.1.4 The Baud Rate Generator Clock (BRGCLK)......................................... 14–14
14.3.1.5 The Synchronization Clock (SYNCCLK, SYNCCLKS) ....................... 14–14
14.3.2 The PIT and RTC Clock (PITRTCLK) ...................................................... 14–15
14.3.3 The Time Base and Decrementer Clock (TMBCLK)................................. 14–16
14.4 Power Distribution.......................................................................................... 14–16
14.4.1 I/O Buffer Power (VDDH) ......................................................................... 14–17
14.4.2 Internal Logic Power (VDDL).................................................................... 14–18
14.4.3 Clock Synthesizer Power (VDDSYN, VSSSYN, VSSYN1) ..................... 14–18

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14.4.4 Keep-Alive Power (KAPWR) .................................................................... 14–18
14.5 Power Control (Low-Power Modes)............................................................... 14–18
14.5.1 Normal High Mode..................................................................................... 14–21
14.5.2 Normal Low Mode...................................................................................... 14–21
14.5.3 Doze High Mode......................................................................................... 14–21
14.5.4 Doze Low Mode ......................................................................................... 14–22
14.5.5 Sleep Mode ................................................................................................. 14–23
14.5.6 Deep-Sleep Mode ....................................................................................... 14–23
14.5.7 Power-Down Mode..................................................................................... 14–24
14.5.7.1 Software Initiation of Power-Down Mode, with Automatic Wake-up... 14–24
14.5.7.2 Maintaining the Real-Time Clock (RTC) During
Shutdown or Power Failure ................................................................14–26
14.5.7.3 Register Lock Mechanism: Protecting SIU
Registers in Power-Down Mode..........................................................14–26
14.5.8 TMIST: Facilitating Nesting of SIU Timer Interrupts................................ 14–27
14.6 Clock and Power Control Registers................................................................ 14–27
14.6.1 System Clock and Reset Control Register (SCCR) .................................... 14–27
14.6.2 PLL, Low-Power, and Reset Control Register (PLPRCR)......................... 14–29
Chapter 15
Memory Controller
15.1 Features............................................................................................................. 15–1
15.2 Basic Architecture............................................................................................. 15–4
15.3 Chip-Select Programming Common to the GPCM and UPM .......................... 15–6
15.3.1 Address Space Programming........................................................................ 15–7
15.3.2 Register Programming Order........................................................................ 15–7
15.3.3 Memory Bank Write Protection.................................................................... 15–7
15.3.4 Address Type Protection............................................................................... 15–7
15.3.5 8-, 16-, and 32-Bit Port Size Configuration.................................................. 15–7
15.3.6 Parity Configuration ..................................................................................... 15–8
15.3.7 Memory Bank Protection Status ................................................................... 15–8
15.3.8 UPM-Specific Registers ............................................................................... 15–8
15.3.9 GPCM-Specific Registers............................................................................. 15–8
15.4 Register Descriptions ........................................................................................ 15–9
15.4.1 Base Registers (BRx).................................................................................... 15–9
15.4.2 Option Registers (ORx) .............................................................................. 15–10
15.4.3 Memory Status Register (MSTAT) ............................................................ 15–13
15.4.4 Machine A Mode Register/Machine B Mode Registers (MxMR) ............. 15–13
15.4.5 Memory Command Register (MCR) .......................................................... 15–15
15.4.6 Memory Data Register (MDR) ................................................................... 15–16
15.4.7 Memory Address Register (MAR) ............................................................. 15–17

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15.4.8 Memory Periodic Timer Prescaler Register (MPTPR)............................... 15–18
15.5 General-Purpose Chip-Select Machine (GPCM)............................................ 15–18
15.5.1 Timing Configuration ................................................................................. 15–19
15.5.1.1 Chip-Select Assertion Timing ................................................................ 15–20
15.5.1.2 Chip-Select and Write Enable Deassertion Timing................................ 15–21
15.5.1.3 Relaxed Timing ...................................................................................... 15–23
15.5.1.4 Output Enable (OE) Timing ................................................................... 15–26
15.5.1.5 Programmable Wait State Configuration................................................ 15–26
15.5.1.6 Extended Hold Time on Read Accesses................................................. 15–26
15.5.2 Boot Chip-Select Operation........................................................................ 15–28
15.5.3 External Asynchronous Master Support ..................................................... 15–29
15.5.4 Special Case: Bursting with External Transfer Acknowledge: .................. 15–30
15.6 User-Programmable Machines (UPMs).......................................................... 15–31
15.6.1 Requests ...................................................................................................... 15–32
15.6.1.1 Internal/External Memory Access Requests........................................... 15–32
15.6.1.2 UPM Periodic Timer Requests ............................................................... 15–33
15.6.1.3 Software Requests—MCR run Command.............................................. 15–33
15.6.1.4 Exception Requests................................................................................. 15–33
15.6.2 Programming the UPM............................................................................... 15–34
15.6.3 Control Signal Generation Timing ............................................................. 15–34
15.6.4 The RAM Array.......................................................................................... 15–37
15.6.4.1 RAM Words............................................................................................ 15–37
15.6.4.2 Chip-Select Signals (CSTx).................................................................... 15–41
15.6.4.3 Byte-Select Signals (BSTx).................................................................... 15–42
15.6.4.4 General-Purpose Signals (GxTx, G0x)................................................... 15–43
15.6.4.5 Loop Control (LOOP)............................................................................. 15–44
15.6.4.6 Exception Pattern Entry (EXEN)............................................................ 15–45
15.6.4.7 Address Multiplexing (AMX) ................................................................ 15–45
15.6.4.8 Transfer Acknowledge and Data Sample Control (UTA, DLT3) .......... 15–50
15.6.4.9 Disable Timer Mechanism (TODT) ....................................................... 15–51
15.6.4.10 The Last Word (LAST) .......................................................................... 15–51
15.6.4.11 The Wait Mechanism (WAEN) .............................................................. 15–51
15.6.4.11.1 Internal and External Synchronous Masters ....................................... 15–51
15.6.4.11.2 External Asynchronous Masters......................................................... 15–52
15.7 Handling Devices with Slow or Variable Access Times ................................ 15–53
15.7.1 Hierarchical Bus Interface Example ........................................................... 15–54
15.7.2 Slow Devices Example ............................................................................... 15–54
15.8 External Master Support ................................................................................. 15–54
15.8.1 Synchronous External Masters ................................................................... 15–54
15.8.2 Asynchronous External Masters ................................................................. 15–55
15.8.3 Special Case: Address Type Signals for External Masters......................... 15–55
15.8.4 UPM Features Supporting External Masters .............................................. 15–55
15.8.4.1 Address Incrementing for External Synchronous Bursting Masters ...... 15–55

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15.8.4.2 Handshake Mechanism for Asynchronous External Masters................. 15–56
15.8.4.3 Special Signal for External Address Multiplexer Control...................... 15–56
15.8.5 External Master Examples .......................................................................... 15–56
15.8.5.1 External Masters and the GPCM ............................................................ 15–56
15.8.5.2 External Masters and the UPM............................................................... 15–58
15.9 Memory System Interface Examples .............................................................. 15–63
15.9.1 Page-Mode DRAM Interface Example....................................................... 15–63
15.9.2 Page Mode Extended Data-Out Interface Example.................................... 15–74
Chapter 16
PCMCIA Interface
16.1 System Configuration ....................................................................................... 16–1
16.2 PCMCIA Module Signal Definitions................................................................ 16–1
16.2.1 PCMCIA Cycle Control Signals................................................................... 16–3
16.2.2 PCMCIA Input Port Signals ......................................................................... 16–4
16.2.3 PCMCIA Output Port Signals (OP[0–4]) ..................................................... 16–5
16.2.4 Other PCMCIA Signals ................................................................................ 16–5
16.3 Operation Description....................................................................................... 16–5
16.3.1 Memory-Only Cards ..................................................................................... 16–6
16.3.2 I/O Cards....................................................................................................... 16–6
16.3.3 Interrupts....................................................................................................... 16–6
16.3.4 Power Control ............................................................................................... 16–7
16.3.5 Reset and Three-State Control...................................................................... 16–7
16.3.6 DMA ............................................................................................................. 16–7
16.4 Programming Model ......................................................................................... 16–8
16.4.1 PCMCIA Interface Input Pins Register (PIPR) ............................................ 16–8
16.4.2 PCMCIA Interface Status Changed Register (PSCR) .................................. 16–9
16.4.3 PCMCIA Interface Enable Register (PER) ................................................ 16–10
16.4.4 PCMCIA Interface General Control Register B (PGCRB) ........................ 16–11
16.4.5 PCMCIA Base Registers 0–7 (PBR0–PBR7)............................................. 16–12
16.4.6 PCMCIA Option Register 0–7 (POR0–POR7) .......................................... 16–12
16.5 PCMCIA Controller Timing Examples .......................................................... 16–16

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Part V
Communications Processor Module
Chapter 17
Communications Processor Module and CPM Timers
17.1 Features............................................................................................................. 17–1
17.2 CPM General-Purpose Timers.......................................................................... 17–4
17.2.1 Features......................................................................................................... 17–5
17.2.2 CPM Timer Operation .................................................................................. 17–6
17.2.2.1 Timer Clock Source.................................................................................. 17–6
17.2.2.2 Timer Reference Count............................................................................. 17–6
17.2.2.3 Timer Capture........................................................................................... 17–6
17.2.2.4 Timer Gating (Timers 1 and 2 only)......................................................... 17–7
17.2.2.5 Cascaded Mode......................................................................................... 17–7
17.2.2.6 Timer 1 and SPKROUT............................................................................ 17–8
17.2.3 CPM Timer Register Set............................................................................... 17–8
17.2.3.1 Timer Global Configuration Register (TGCR)......................................... 17–8
17.2.4 Timer Mode Registers (TMR1–TMR4) ....................................................... 17–9
17.2.4.1 Timer Reference Registers (TRR1–TRR4) ............................................ 17–10
17.2.4.2 Timer Capture Registers (TCR1–TCR4)................................................ 17–10
17.2.4.3 Timer Counter Registers (TCN1–TCN4) ............................................... 17–11
17.2.4.4 Timer Event Registers (TER1–TER4).................................................... 17–11
17.2.5 Timer Initialization Examples .................................................................... 17–12
Chapter 18
Communications Processor
18.1 Features............................................................................................................. 18–1
18.2 Communicating with the Core.......................................................................... 18–2
18.3 Communicating with the Peripherals................................................................ 18–2
18.4 CP Microcode Revision Number ...................................................................... 18–3
18.5 CP Register Set and CP Commands ................................................................. 18–4
18.5.1 RISC Controller Configuration Register (RCCR) ........................................ 18–4
18.5.2 RISC Microcode Development Support Control Register (RMDS) ............ 18–5
18.5.3 CP Command Register (CPCR).................................................................... 18–6
18.5.4 CP Commands .............................................................................................. 18–7
18.5.4.1 CP Command Examples ........................................................................... 18–9
18.5.4.2 CP Command Execution Latency............................................................. 18–9
18.6 Dual-Port RAM................................................................................................. 18–9
18.6.1 System RAM and Microcode Packages...................................................... 18–11
18.6.2 The Buffer Descriptor (BD)........................................................................ 18–12