Atmel AT91 Series User manual

Features
•Incorporates the ARM7TDMI®ARM®Thumb®Processor
– High-performance 32-bit RISC Architecture
– High-density 16-bit Instruction Set
– Leader in MIPS/Watt
– Embedded ICE In-circuit Emulation, Debug Communication Channel Support
•Internal High-speed Flash
– 256 Kbytes (AT91SAM7XC256) Organized in 1024 Pages of 256 Bytes
– 128 Kbytes (AT91SAM7XC128) Organized in 512 Pages of 256 Bytes
– Single Cycle Access at Up to 30 MHz in Worst Case Conditions
– Prefetch Buffer Optimizing Thumb Instruction Execution at Maximum Speed
– Page Programming Time: 6 ms, Including Page Auto-erase,
Full Erase Time: 15 ms
– 10,000 Write Cycles, 10-year Data Retention Capability,
Sector Lock Capabilities, Flash Security Bit
– Fast Flash Programming Interface for High Volume Production
•Internal High-speed SRAM, Single-cycle Access at Maximum Speed
– 64 Kbytes (AT91SAM7XC256)
– 32 Kbytes (AT91SAM7XC128)
•Memory Controller (MC)
– Embedded Flash Controller, Abort Status and Misalignment Detection
•Reset Controller (RSTC)
– Based on Power-on Reset Cells and Low-power Factory-calibrated Brownout
Detector
– Provides External Reset Signal Shaping and Reset Source Status
•Clock Generator (CKGR)
– Low-power RC Oscillator, 3 to 20 MHz On-chip Oscillator and one PLL
•Power Management Controller (PMC)
– Power Optimization Capabilities, Including Slow Clock Mode (Down to 500 Hz) and
Idle Mode
– Four Programmable External Clock Signals
•Advanced Interrupt Controller (AIC)
– Individually Maskable, Eight-level Priority, Vectored Interrupt Sources
– Two External Interrupt Sources and One Fast Interrupt Source, Spurious Interrupt
Protected
•Debug Unit (DBGU)
– 2-wire UART and Support for Debug Communication Channel interrupt,
Programmable ICE Access Prevention
•Periodic Interval Timer (PIT)
– 20-bit Programmable Counter plus 12-bit Interval Counter
•Windowed Watchdog (WDT)
– 12-bit key-protected Programmable Counter
– Provides Reset or Interrupt Signals to the System
– Counter May Be Stopped While the Processor is in Debug State or in Idle Mode
•Real-time Timer (RTT)
– 32-bit Free-running Counter with Alarm
– Runs Off the Internal RC Oscillator
•Two Parallel Input/Output Controllers (PIO)
– Sixty-two Programmable I/O Lines Multiplexed with up to Two Peripheral I/Os
– Input Change Interrupt Capability on Each I/O Line
– Individually Programmable Open-drain, Pull-up Resistor and Synchronous Output
AT91 ARM®
Thumb®-based
Microcontrollers
AT91SAM7XC256
AT91SAM7XC128
Summary
Preliminary
6209AS–ATARM–20-Oct-05
Note: This is a summary document. A complete document
is available on our Web site at www.atmel.com.

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6209AS–ATARM–20-Oct-05
AT91SAM7XC256/128 Preliminary
•Seventeen Peripheral DMA Controller (PDC) Channels
•One Advanced Encryption System (AES)
– 128-bit Key Algorithm, Compliant with FIPS PUB 197 Specifications
– Buffer Encryption/Decryption Capabilities with PDC
•One Triple Data Encryption System (TDES)
– Two-key or Three-key Algorithms, Compliant with FIPS PUB 46-3 Specifications
– Optimized for Triple Data Encryption Capability
•One USB 2.0 Full Speed (12 Mbits per second) Device Port
– On-chip Transceiver, 1352-byte Configurable Integrated FIFOs
•One Ethernet MAC 10/100 base-T
– Media Independent Interface (MII) or Reduced Media Independent Interface (RMII)
– Integrated 28-byte FIFOs and Dedicated DMA Channels for Transmit and Receive
•One Part 2.0A and Part 2.0B Compliant CAN Controller
– Eight Fully-programmable Message Object Mailboxes, 16-bit Time Stamp Counter
•One Synchronous Serial Controller (SSC)
– Independent Clock and Frame Sync Signals for Each Receiver and Transmitter
– I²S Analog Interface Support, Time Division Multiplex Support
– High-speed Continuous Data Stream Capabilities with 32-bit Data Transfer
•Two Universal Synchronous/Asynchronous Receiver Transmitters (USART)
– Individual Baud Rate Generator, IrDA Infrared Modulation/Demodulation
– Support for ISO7816 T0/T1 Smart Card, Hardware Handshaking, RS485 Support
– Full Modem Line Support on USART1
•Two Master/Slave Serial Peripheral Interfaces (SPI)
– 8- to 16-bit Programmable Data Length, Four External Peripheral Chip Selects
•One Three-channel 16-bit Timer/Counter (TC)
– Three External Clock Inputs, Two Multi-purpose I/O Pins per Channel
– Double PWM Generation, Capture/Waveform Mode, Up/Down Capability
•One Four-channel 16-bit Power Width Modulation Controller (PWMC)
•One Two-wire Interface (TWI)
– Master Mode Support Only, All Two-wire Atmel EEPROMs Supported
•One 8-channel 10-bit Analog-to-Digital Converter, Four Channels Multiplexed with Digital I/Os
•SAM-BA™Boot Assistance
– Default Boot program
– Interface with SAM-BA Graphic User Interface
•IEEE 1149.1 JTAG Boundary Scan on All Digital Pins
•5V-tolerant I/Os, Including Four High-current Drive I/O lines, Up to 16 mA Each
•Power Supplies
– Embedded 1.8V Regulator, Drawing up to 100 mA for the Core and External Components
– 3.3V VDDIO I/O Lines Power Supply, Independent 3.3V VDDFLASH Flash Power Supply
– 1.8V VDDCORE Core Power Supply with Brownout Detector
•Fully Static Operation: Up to 55 MHz at 1.65V and 85°C Worst Case Conditions
•Available in a 100-lead LQFP Green Package

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AT91SAM7XC256/128 Preliminary
1. Description
Atmel's AT91SAM7XC256/128 is a member of a series of highly integrated Flash microcontrol-
lers based on the 32-bit ARM RISC processor. It features 256/128 Kbyte high-speed Flash and
64/32 Kbyte SRAM, a large set of peripherals, including an 802.3 Ethernet MAC, a CAN control-
ler, an AES 128 Encryption accelerator and a Triple Data Encryption System. A complete set of
system functions minimizes the number of external components.
The embedded Flash memory can be programmed in-system via the JTAG-ICE interface or via
a parallel interface on a production programmer prior to mounting. Built-in lock bits and a secu-
rity bit protect the firmware from accidental overwrite and preserve its confidentiality.
The AT91SAM7XC256/128 system controller includes a reset controller capable of managing
the power-on sequence of the microcontroller and the complete system. Correct device opera-
tion can be monitored by a built-in brownout detector and a watchdog running off an integrated
RC oscillator.
By combining the ARM7TDMI processor with on-chip Flash and SRAM, and a wide range of
peripheral functions, including USART, SPI, CAN Controller, Ethernet MAC, AES 128 accelera-
tor, TDES, Timer Counter, RTT and Analog-to-Digital Converters on a monolithic chip, the
AT91SAM7XC256/128 is a powerful device that provides a flexible, cost-effective solution to
many embedded control applications requiring secure communication over, for example, Ether-
net, CAN wired and Zigbee wireless networks.
2. Configuration Summary of the AT91SAM7XC256 and AT91SAM7XC128
The AT91SAM7XC256 and AT91SAM7XC128 differ only in memory sizes. Table 2-1 summa-
rizes the configurations of the two devices.
Table 2-1. Configuration Summary
Device Flash SRAM
AT91SAM7XC256 256K bytes 64K bytes
AT91SAM7XC128 128K bytes 32K bytes

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AT91SAM7XC256/128 Preliminary
3. AT91SAM7XC256/128 Block Diagram
Figure 3-1. AT91SAM7XC256/128 Block Diagram
TDI
TDO
TMS
TCK
NRST
FIQ
IRQ0-IRQ1
PCK0-PCK3
PMC
Peripheral Bridge
Peripheral DMA
Controller
AIC
PLL
RCOSC
SRAM
64/32 Kbytes
ARM7TDMI
Processor
ICE
JTAG
SCAN
JTAGSEL
PIOA
USART0
SSC
Timer Counter
RXD0
TXD0
SCK0
RTS0
CTS0
SPI0_NPCS0
SPI0_NPCS1
SPI0_NPCS2
SPI0_NPCS3
SPI0_MISO
SPI0_MOSI
SPI0_SPCK
Flash
256/128 Kbytes
Reset
Controller
DRXD
DTXD
TF
TK
TD
RD
RK
RF
TCLK0
TCLK1
TCLK2
TIOA0
TIOB0
TIOA1
TIOB1
TIOA2
TIOB2
Memory Controller
Abort
Status
Address
Decoder
Misalignment
Detection
PIO
PIO
APB
POR
Embedded
Flash
Controller
AD0
AD1
AD2
AD3
ADTRG
PLLRC
17 Channels
PDC
PDC
USART1
RXD1
TXD1
SCK1
RTS1
CTS1
DCD1
DSR1
DTR1
RI1
PDC
PDC
PDC
PDC
SPI0
PDC
ADC
ADVREF
PDC
PDC
TC0
TC1
TC2
TWD
TWCK
TWI
OSC
XIN
XOUT
VDDIN
PWMC
PWM0
PWM1
PWM2
PWM3
1.8 V
Voltage
Regulator
USB Device
FIFO DDM
DDP
Transceiver
GND
VDDOUT
BOD
VDDCORE
VDDCORE
VDDFLASH
AD4
AD5
AD6
AD7
VDDFLASH
Fast Flash
Programming
Interface
ERASE
PIO
PGMD0-PGMD15
PGMNCMD
PGMEN0-PGMEN1
PGMRDY
PGMNVALID
PGMNOE
PGMCK
PGMM0-PGMM3
VDDIO
TST
DBGU PDC
PDC
PIT
WDT
RTT
System Controller
VDDCORE
CAN CANRX
CANTX
PIO
Ethernet MAC 10/100
ETXCK-ERXCK-EREFCK
ETXEN-ETXER
ECRS-ECOL, ECRSDV
ERXER-ERXDV
ERX0-ERX3
ETX0-ETX3
EMDC
EMDIO
DMA
FIFO
PIOB
SPI1_NPCS0
SPI1_NPCS1
SPI1_NPCS2
SPI1_NPCS3
SPI1_MISO
SPI1_MOSI
SPI1_SPCK
PDC
PDC
SPI1
AES 128
PDC
PDC
EF100
SAM-BA
TDES
PDC
PDC
ROM
VDDFLASH

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AT91SAM7XC256/128 Preliminary
4. Signal Description
Table 4-1. Signal Description List
Signal Name Function Type
Active
Level Comments
Power
VDDIN Voltage Regulator and ADC Power
Supply Input Power 3V to 3.6V
VDDOUT Voltage Regulator Output Power 1.85V
VDDFLASH Flash and USB Power Supply Power 3V to 3.6V
VDDIO I/O Lines Power Supply Power 3V to 3.6V
VDDCORE Core Power Supply Power 1.65V to 1.95V
VDDPLL PLL Power 1.65V to 1.95V
GND Ground Ground
Clocks, Oscillators and PLLs
XIN Main Oscillator Input Input
XOUT Main Oscillator Output Output
PLLRC PLL Filter Input
PCK0 - PCK3 Programmable Clock Output Output
ICE and JTAG
TCK Test Clock Input No pull-up resistor
TDI Test Data In Input No pull-up resistor.
TDO Test Data Out Output
TMS Test Mode Select Input No pull-up resistor.
JTAGSEL JTAG Selection Input Pull-down resistor.
Flash Memory
ERASE Flash and NVM Configuration Bits Erase
Command Input High Pull-down resistor
Reset/Test
NRST Microcontroller Reset I/O Low Pull-Up resistor, Open Drain
Output
TST Test Mode Select Input High Pull-down resistor
Debug Unit
DRXD Debug Receive Data Input
DTXD Debug Transmit Data Output
AIC
IRQ0 - IRQ1 External Interrupt Inputs Input
FIQ Fast Interrupt Input Input
PIO
PA0 - PA30 Parallel IO Controller A I/O Pulled-up input at reset
PB0 - PB30 Parallel IO Controller B I/O Pulled-up input at reset

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AT91SAM7XC256/128 Preliminary
USB Device Port
DDM USB Device Port Data - Analog
DDP USB Device Port Data + Analog
USART
SCK0 - SCK1 Serial Clock I/O
TXD0 - TXD1 Transmit Data I/O
RXD0 - RXD1 Receive Data Input
RTS0 - RTS1 Request To Send Output
CTS0 - CTS1 Clear To Send Input
DCD1 Data Carrier Detect Input
DTR1 Data Terminal Ready Output
DSR1 Data Set Ready Input
RI1 Ring Indicator Input
Synchronous Serial Controller
TD Transmit Data Output
RD Receive Data Input
TK Transmit Clock I/O
RK Receive Clock I/O
TF Transmit Frame Sync I/O
RF Receive Frame Sync I/O
Timer/Counter
TCLK0 - TCLK2 External Clock Inputs Input
TIOA0 - TIOA2 I/O Line A I/O
TIOB0 - TIOB2 I/O Line B I/O
PWM Controller
PWM0 - PWM3 PWM Channels Output
Serial Peripheral Interface - SPIx
SPIx_MISO Master In Slave Out I/O
SPIx_MOSI Master Out Slave In I/O
SPIx_SPCK SPI Serial Clock I/O
SPIx_NPCS0 SPI Peripheral Chip Select 0 I/O Low
SPIx_NPCS1-NPCS3 SPI Peripheral Chip Select 1 to 3 Output Low
Two-wire Interface
TWD Two-wire Serial Data I/O
TWCK Two-wire Serial Clock I/O
Table 4-1. Signal Description List (Continued)
Signal Name Function Type
Active
Level Comments

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AT91SAM7XC256/128 Preliminary
Analog-to-Digital Converter
AD0-AD3 Analog Inputs Analog Digital pulled-up inputs at reset
AD4-AD7 Analog Inputs Analog Analog Inputs
ADTRG ADC Trigger Input
ADVREF ADC Reference Analog
Fast Flash Programming Interface
PGMEN0-PGMEN1 Programming Enabling Input
PGMM0-PGMM3 Programming Mode Input
PGMD0-PGMD15 Programming Data I/O
PGMRDY Programming Ready Output High
PGMNVALID Data Direction Output Low
PGMNOE Programming Read Input Low
PGMCK Programming Clock Input
PGMNCMD Programming Command Input Low
CAN Controller
CANRX CAN Input Input
CANTX CAN Output Output
Ethernet MAC 10/100
EREFCK Reference Clock Input RMII only
ETXCK Transmit Clock Input MII only
ERXCK Receive Clock Input MII only
ETXEN Transmit Enable Output
ETX0 - ETX3 Transmit Data Output ETX0 - ETX1 only in RMII
ETXER Transmit Coding Error Output MII only
ERXDV Receive Data Valid Input MII only
ECRSDV Carrier Sense and Data Valid Input RMII only
ERX0 - ERX3 Receive Data Input ERX0 - ERX1 only in RMII
ERXER Receive Error Input
ECRS Carrier Sense Input MII only
ECOL Collision Detected Input MII only
EMDC Management Data Clock Output
EMDIO Management Data Input/Output I/O
EF100 Force 100 Mbits/sec. Output High RMII only
Table 4-1. Signal Description List (Continued)
Signal Name Function Type
Active
Level Comments

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AT91SAM7XC256/128 Preliminary
5. Package
The AT91SAM7XC256/128 is available in 100-lead LQFP package.
5.1 100-lead LQFP Mechanical Overview
Figure 5-1 shows the orientation of the 100-lead LQFP package. A detailed mechanical descrip-
tion is given in the Mechanical Characteristics section of the full datasheet.
Figure 5-1. 100-lead LQFP Package Pinout (Top View)
5.2 AT91SAM7XC256/128 Pinout
51
76
75
50
26
25
1
100
Table 5-1. Pinout in 100-lead TQFP Package
1 ADVREF 26 PA18/PGMD6 51 TDI 76 TDO
2 GND 27 PB9 52 GND 77 JTAGSEL
3 AD4 28 PB8 53 PB16 78 TMS
4 AD5 29 PB14 54 PB4 79 TCK
5 AD6 30 PB13 55 PA23/PGMD11 80 PA30
6 AD7 31 PB6 56 PA24/PGMD12 81 PA0/PGMEN0
7 VDDOUT 32 GND 57 NRST 82 PA1/PGMEN1
8 VDDIN 33 VDDIO 58 TST 83 GND
9 PB27/AD0 34 PB5 59 PA25/PGMD13 84 VDDIO
10 PB28/AD1 35 PB15 60 PA26/PGMD14 85 PA3
11 PB29/AD2 36 PB17 61 VDDIO 86 PA2
12 PB30/AD3 37 VDDCORE 62 VDDCORE 87 VDDCORE
13 PA8/PGMM0 38 PB7 63 PB18 88 PA4/PGMNCMD
14 PA9/PGMM1 39 PB12 64 PB19 89 PA5/PGMRDY
15 VDDCORE 40 PB0 65 PB20 90 PA6/PGMNOE
16 GND 41 PB1 66 PB21 91 PA7/PGMNVALID
17 VDDIO 42 PB2 67 PB22 92 ERASE
18 PA10/PGMM2 43 PB3 68 GND 93 DDM
19 PA11/PGMM3 44 PB10 69 PB23 94 DDP
20 PA12/PGMD0 45 PB11 70 PB24 95 VDDFLASH
21 PA13/PGMD1 46 PA19/PGMD7 71 PB25 96 GND
22 PA14/PGMD2 47 PA20/PGMD8 72 PB26 97 XIN/PGMCK
23 PA15/PGMD3 48 VDDIO 73 PA27/PGMD15 98 XOUT
24 PA16/PGMD4 49 PA21/PGMD9 74 PA28 99 PLLRC
25 PA17/PGMD5 50 PA22/PGMD10 75 PA29 100 VDDPLL

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AT91SAM7XC256/128 Preliminary
6. Power Considerations
6.1 Power Supplies
The AT91SAM7XC256/128 has six types of power supply pins and integrates a voltage regula-
tor, allowing the device to be supplied with only one voltage. The six power supply pin types are:
• VDDIN pin. It powers the voltage regulator and the ADC; voltage ranges from 3.0V to 3.6V,
3.3V nominal. In order to decrease current consumption, if the voltage regulator and the ADC
are not used, VDDIN, ADVREF, AD5, AD6 and AD7 should be connected to GND. In this
case, VDDOUT should be left unconnected.
• VDDOUT pin. It is the output of the 1.8V voltage regulator.
• VDDIO pin. It powers the I/O lines; voltage ranges from 3.0V to 3.6V, 3.3V nominal.
• VDDFLASH pin. It powers the USB transceivers and a part of the Flash and is required for
the Flash to operate correctly; voltage ranges from 3.0V to 3.6V, 3.3V nominal.
• VDDCORE pins. They power the logic of the device; voltage ranges from 1.65V to 1.95V,
1.8V typical. It can be connected to the VDDOUT pin with decoupling capacitor. VDDCORE
is required for the device, including its embedded Flash, to operate correctly.
• VDDPLL pin. It powers the oscillator and the PLL. It can be connected directly to the
VDDOUT pin.
No separate ground pins are provided for the different power supplies. Only GND pins are pro-
vided and should be connected as shortly as possible to the system ground plane.
6.2 Power Consumption
The AT91SAM7XC256/128 has a static current of less than 60 µA on VDDCORE at 25°C,
including the RC oscillator, the voltage regulator and the power-on reset when the brownout
detector is deactivated. Activating the brownout detector adds 28 µA static current.
The dynamic power consumption on VDDCORE is less than 90 mA at full speed when running
out of the Flash. Under the same conditions, the power consumption on VDDFLASH does not
exceed 10 mA.
6.3 Voltage Regulator
The AT91SAM7XC256/128 embeds a voltage regulator that is managed by the System
Controller.
In Normal Mode, the voltage regulator consumes less than 100 µA static current and draws 100
mA of output current.
The voltage regulator also has a Low-power Mode. In this mode, it consumes less than 25 µA
static current and draws 1 mA of output current.
Adequate output supply decoupling is mandatory for VDDOUT to reduce ripple and avoid oscil-
lations. The best way to achieve this is to use two capacitors in parallel: one external 470 pF (or
1 nF) NPO capacitor should be connected between VDDOUT and GND as close to the chip as
possible. One external 2.2 µF (or 3.3 µF) X7R capacitor should be connected between VDDOUT
and GND.

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AT91SAM7XC256/128 Preliminary
Adequate input supply decoupling is mandatory for VDDIN in order to improve startup stability
and reduce source voltage drop. The input decoupling capacitor should be placed close to the
chip. For example, two capacitors can be used in parallel: 100 nF NPO and 4.7 µF X7R.
6.4 Typical Powering Schematics
The AT91SAM7XC256/128 supports a 3.3V single supply mode. The internal regulator input
connected to the 3.3V source and its output feeds VDDCORE and the VDDPLL. Figure 6-1
shows the power schematics to be used for USB bus-powered systems.
Figure 6-1. 3.3V System Single Power Supply Schematic
Power Source
ranges
from 4.5V (USB)
to 18V
3.3V
VDDIN
Voltage
Regulator
VDDOUT
VDDIO
DC/DC Converter
VDDCORE
VDDFLASH
VDDPLL

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AT91SAM7XC256/128 Preliminary
7. I/O Lines Considerations
7.1 JTAG Port Pins
TMS, TDI and TCK are schmitt trigger inputs and are not 5-V tolerant. TMS, TDI and TCK do not
integrate a pull-up resistor.
TDO is an output, driven at up to VDDIO, and has no pull-up resistor.
The JTAGSEL pin is used to select the JTAG boundary scan when asserted at a high level. The
JTAGSEL pin integrates a permanent pull-down resistor of about 15 kΩ to GND, so that it can be
left unconnected for normal operations.
7.2 Test Pin
The TST pin is used for manufacturing test or fast programming mode of the
AT91SAM7XC256/128 when asserted high. The TST pin integrates a permanent pull-down
resistor of about 15 kΩto GND, so that it can be left unconnected for normal operations.
To enter fast programming mode, the TST pin and the PA0 and PA1 pins should be tied high
and PA2 tied to low.
Driving the TST pin at a high level while PA0 or PA1 is driven at 0 leads to unpredictable results.
7.3 Reset Pin
The NRST pin is bidirectional with an open drain output buffer. It is handled by the on-chip reset
controller and can be driven low to provide a reset signal to the external components or asserted
low externally to reset the microcontroller. There is no constraint on the length of the reset pulse,
and the reset controller can guarantee a minimum pulse length. This allows connection of a sim-
ple push-button on the NRST pin as system user reset, and the use of the signal NRST to reset
all the components of the system.
The NRST pin integrates a permanent pull-up resistor to VDDIO.
7.4 ERASE Pin
The ERASE pin is used to re-initialize the Flash content and some of its NVM bits. It integrates a
permanent pull-down resistor of about 15 kΩto GND, so that it can be left unconnected for nor-
mal operations.
This pin is debounced by the RC oscillator to improve the glitch tolerance. Minimum debouncing
time is 200 ms.
7.5 PIO Controller Lines
All the I/O lines, PA0 to PA30 and PB0 to PB30, are 5V-tolerant and all integrate a programma-
ble pull-up resistor. Programming of this pull-up resistor is performed independently for each I/O
line through the PIO controllers.
5V-tolerant means that the I/O lines can drive voltage level according to VDDIO, but can be
driven with a voltage of up to 5.5V. However, driving an I/O line with a voltage over VDDIO while
the programmable pull-up resistor is enabled can lead to unpredictable results. Care should be
taken, in particular at reset, as all the I/O lines default to input with pull-up resistor enabled at
reset.

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AT91SAM7XC256/128 Preliminary
7.6 I/O Lines Current Drawing
The PIO lines PA0 to PA3 are high-drive current capable. Each of these I/O lines can drive up to
16 mA permanently.
The remaining I/O lines can draw only 8 mA.
However, the total current drawn by all the I/O lines cannot exceed 200 mA.

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AT91SAM7XC256/128 Preliminary
8. Processor and Architecture
8.1 ARM7TDMI Processor
• RISC processor based on ARMv4T Von Neumann architecture
– Runs at up to 55 MHz, providing 0.9 MIPS/MHz
• Two instruction sets
–ARM
®high-performance 32-bit instruction set
–Thumb
®high code density 16-bit instruction set
• Three-stage pipeline architecture
– Instruction Fetch (F)
– Instruction Decode (D)
– Execute (E)
8.2 Debug and Test Features
• Integrated embedded in-circuit emulator
– Two watchpoint units
– Test access port accessible through a JTAG protocol
– Debug communication channel
• Debug Unit
–Two-pinUART
– Debug communication channel interrupt handling
– Chip ID Register
• IEEE1149.1 JTAG Boundary-scan on all digital pins
8.3 Memory Controller
• Programmable Bus Arbiter
– Handles requests from the ARM7TDMI, the Ethernet MAC and the Peripheral DMA
Controller
• Address decoder provides selection signals for
– Three internal 1 Mbyte memory areas
– One 256 Mbyte embedded peripheral area
• Abort Status Registers
– Source, Type and all parameters of the access leading to an abort are saved
– Facilitates debug by detection of bad pointers
• Misalignment Detector
– Alignment checking of all data accesses
– Abort generation in case of misalignment
• Remap Command
– Remaps the SRAM in place of the embedded non-volatile memory
– Allows handling of dynamic exception vectors

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AT91SAM7XC256/128 Preliminary
• Embedded Flash Controller
– Embedded Flash interface, up to three programmable wait states
– Prefetch buffer, buffering and anticipating the 16-bit requests, reducing the required
wait states
– Key-protected program, erase and lock/unlock sequencer
– Single command for erasing, programming and locking operations
– Interrupt generation in case of forbidden operation
8.4 Peripheral DMA Controller
• Handles data transfer between peripherals and memories
• Seventeen channels
– Two for each USART
– Two for the Debug Unit
– Two for the Serial Synchronous Controller
– Two for each Serial Peripheral Interface
– Two for the Advanced Encryption Standard 128-bit accelerator
– Two for the Triple Data Encryption Standard 128-bit accelerator
– One for the Analog-to-digital Converter
• Low bus arbitration overhead
– One Master Clock cycle needed for a transfer from memory to peripheral
– Two Master Clock cycles needed for a transfer from peripheral to memory
• Next Pointer management for reducing interrupt latency requirements

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AT91SAM7XC256/128 Preliminary
9. Memory
9.1 AT91SAM7XC256
• 256 Kbytes of Flash Memory
– 1024 pages of 256 bytes
– Fast access time, 30 MHz single-cycle access in Worst Case conditions
– Page programming time: 6 ms, including page auto-erase
– Page programming without auto-erase: 3 ms
– Full chip erase time: 15 ms
– 10,000 write cycles, 10-year data retention capability
– 16 lock bits, each protecting 16 sectors of 64 pages
– Protection Mode to secure contents of the Flash
• 64 Kbytes of Fast SRAM
– Single-cycle access at full speed
9.2 AT91SAM7XC128
• 128 Kbytes of Flash Memory
– 512 pages of 256 bytes
– Fast access time, 30 MHz single-cycle access in Worst Case conditions
– Page programming time: 6 ms, including page auto-erase
– Page programming without auto-erase: 3 ms
– Full chip erase time: 15 ms
– 10,000 write cycles, 10-year data retention capability
– 8 lock bits, each protecting 8 sectors of 64 pages
– Protection Mode to secure contents of the Flash
• 32 Kbytes of Fast SRAM
– Single-cycle access at full speed

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9.3 Memory Mapping
9.3.1 Internal RAM
• The AT91SAM7XC256 embeds a high-speed 64-Kbyte SRAM bank
• The AT91SAM7XC128 embeds a high-speed 32-Kbyte SRAM bank.
After reset and until the Remap Command is performed, the SRAM is only accessible at address
0x0020 0000. After Remap, the SRAM also becomes available at address 0x0.
9.3.2 Internal ROM
The AT91SAM7XC256/128 embeds an Internal ROM. At any time, the ROM is mapped at
address 0x30 0000. The ROM contains FFPI and SAM-BA program.
9.3.3 Internal Flash
• The AT91SAM7XC256 features one bank of 256 Kbytes of Flash
• The AT91SAM7XC128 features one bank of 128 Kbytes of Flash.
At any time, the Flash is mapped to address 0x0010 0000. It is also accessible at address 0x0
after the reset and before the Remap Command.
A general purpose NVM (GPNVM) bit is used to boot either on the ROM (default) or from the
Flash.
This GPNVM bit can be cleared or set respectively through the commands “Clear General-pur-
pose NVM Bit” and “Set General-purpose NVM Bit” of the EFC User Interface.
Setting the GPNVM Bit 2 selects the boot from the Flash. Asserting ERASE clears the GPNVM
Bit 2 and thus selects the boot from the ROM by default.
Figure 9-1. Internal Memory Mapping with GPNVM Bit 2 = 0 (default)
256M Bytes
ROM Before Remap
SRAM After Remap
Undefined Areas
(Abort)
0x000F FFFF
0x001F FFFF
0x002F FFFF
0x0FFF FFFF
1 M Bytes
1 M Bytes
1 M Bytes
252 M Bytes
Internal FLASH
Internal SRAM
0x0000 0000
0x0010 0000
0x0020 0000
0x0030 0000
Internal ROM
0x003F FFFF
0x0040 0000
1 M Bytes

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6209AS–ATARM–20-Oct-05
AT91SAM7XC256/128 Preliminary
Figure 9-2. Internal Memory Mapping with GPNVM Bit 2 = 1
9.4 Embedded Flash
9.4.1 Flash Overview
• The Flash of the AT91SAM7XC256 is organized in 1024 pages of 256 bytes. It reads as
65,536 32-bit words.
• The Flash of the AT91SAM7XC128 is organized in 512 pages of 256 bytes. It reads as
32,768 32-bit words.
The Flash contains a 256-byte write buffer, accessible through a 32-bit interface.
The Flash benefits from the integration of a power reset cell and from the brownout detector.
This prevents code corruption during power supply changes, even in the worst conditions.
When Flash is not used (read or write access), it is automatically placed into standby mode.
9.4.2 Embedded Flash Controller
The Embedded Flash Controller (EFC) manages accesses performed by the masters of the sys-
tem. It enables reading the Flash and writing the write buffer. It also contains a User Interface,
mapped within the Memory Controller on the APB. The User Interface allows:
• programming of the access parameters of the Flash (number of wait states, timings, etc.)
• starting commands such as full erase, page erase, page program, NVM bit set, NVM bit
clear, etc.
• getting the end status of the last command
• getting error status
• programming interrupts on the end of the last commands or on errors
The Embedded Flash Controller also provides a dual 32-bit Prefetch Buffer that optimizes 16-bit
access to the Flash. This is particularly efficient when the processor is running in Thumb mode.
256M Bytes
Flash Before Remap
SRAM After Remap
Undefined Areas
(Abort)
0x000F FFFF
0x001F FFFF
0x002F FFFF
0x0FFF FFFF
1 M Bytes
1 M Bytes
1 M Bytes
252 M Bytes
Internal FLASH
Internal SRAM
0x0000 0000
0x0010 0000
0x0020 0000
0x0030 0000
Internal ROM
0x003F FFFF
0x0040 0000
1 M Bytes

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AT91SAM7XC256/128 Preliminary
9.4.3 Lock Regions
9.4.3.1 AT91SAM7XC256
The Embedded Flash Controller manages 16 lock bits to protect 16 regions of the flash against
inadvertent flash erasing or programming commands. The AT91SAM7XC256 contains 16 lock
regions and each lock region contains 64 pages of 256 bytes. Each lock region has a size of 16
Kbytes.
If a locked-region’s erase or program command occurs, the command is aborted and the EFC
trigs an interrupt.
The 16 NVM bits are software programmable through the EFC User Interface. The command
“Set Lock Bit” enables the protection. The command “Clear Lock Bit” unlocks the lock region.
Asserting the ERASE pin clears the lock bits, thus unlocking the entire Flash.
9.4.3.2 AT91SAM7XC128
The Embedded Flash Controller manages 8 lock bits to protect 8 regions of the flash against
inadvertent flash erasing or programming commands. The AT91SAM7XC128 contains 8 lock
regions and each lock region contains 64 pages of 256 bytes. Each lock region has a size of 16
Kbytes.
If a locked-region’s erase or program command occurs, the command is aborted and the EFC
trigs an interrupt.
The 8 NVM bits are software programmable through the EFC User Interface. The command “Set
Lock Bit” enables the protection. The command “Clear Lock Bit” unlocks the lock region.
Asserting the ERASE pin clears the lock bits, thus unlocking the entire Flash.
9.4.4 Security Bit Feature
The AT91SAM7XC256/128 features a security bit, based on a specific NVM-Bit. When the secu-
rity is enabled, any access to the Flash, either through the ICE interface or through the Fast
Flash Programming Interface, is forbidden. This ensures the confidentiality of the code pro-
grammed in the Flash.
This security bit can only be enabled, through the Command “Set Security Bit” of the EFC User
Interface. Disabling the security bit can only be achieved by asserting the ERASE pin at 1, and
after a full flash erase is performed. When the security bit is deactivated, all accesses to the
flash are permitted.
It is important to note that the assertion of the ERASE pin should always be longer than 200 ms.
As the ERASE pin integrates a permanent pull-down, it can be left unconnected during normal
operation. However, it is safer to connect it directly to GND for the final application.
9.4.5 Non-volatile Brownout Detector Control
Two general purpose NVM (GPNVM) bits are used for controlling the brownout detector (BOD),
so that even after a power loss, the brownout detector operations remain in their state.
These two GPNVM bits can be cleared or set respectively through the commands “Clear Gen-
eral-purpose NVM Bit” and “Set General-purpose NVM Bit” of the EFC User Interface.

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AT91SAM7XC256/128 Preliminary
• GPNVM Bit 0 is used as a brownout detector enable bit. Setting the GPNVM Bit 0 enables
the BOD, clearing it disables the BOD. Asserting ERASE clears the GPNVM Bit 0 and thus
disables the brownout detector by default.
• The GPNVM Bit 1 is used as a brownout reset enable signal for the reset controller. Setting
the GPNVM Bit 1 enables the brownout reset when a brownout is detected, Clearing the
GPNVM Bit 1 disables the brownout reset. Asserting ERASE disables the brownout reset by
default.
9.4.6 Calibration Bits
Eight NVM bits are used to calibrate the brownout detector and the voltage regulator. These bits
are factory configured and cannot be changed by the user. The ERASE pin has no effect on the
calibration bits.
9.5 Fast Flash Programming Interface
The Fast Flash Programming Interface allows programming the device through either a serial
JTAG interface or through a multiplexed fully-handshaked parallel port. It allows gang-program-
ming with market-standard industrial programmers.
The FFPI supports read, page program, page erase, full erase, lock, unlock and protect
commands.
The Fast Flash Programming Interface is enabled and the Fast Programming Mode is entered
when the TST pin and the PA0 and PA1 pins are all tied high.
9.6 SAM-BA Boot Assistant
The SAM-BA Boot Assistant is a default Boot Program that provides an easy way to program in-
situ the on-chip Flash memory.
The SAM-BA Boot Assistant supports serial communication via the DBGU or the USB Device
Port.
• Communication via the DBGU supports a wide range of crystals from 3 to 20 MHz via
software auto-detection.
• Communication via the USB Device Port is limited to an 18.432 MHz crystal.
The SAM-BA Boot provides an interface with SAM-BA Graphic User Interface (GUI).
The SAM-BA Boot is in ROM and is mapped in Flash at address 0x0 when the GPNVM Bit 2 is
set to 0.

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AT91SAM7XC256/128 Preliminary
10. System Controller
The System Controller manages all vital blocks of the microcontroller: interrupts, clocks, power,
time, debug and reset.
Figure 10-1. System Controller Block Diagram
NRST
SLCK
Advanced
Interrupt
Controller
Real-Time
Timer
Periodic
Interval
Timer
Reset
Controller
PA0-PA30
periph_nreset
System Controller
Watchdog
Timer
wdt_fault
WDRPROC
PIO
Controller
POR
BOD
RCOSC
gpnvm[0]
cal
en
Power
Management
Controller
OSC
PLL
XIN
XOUT
PLLRC
MAINCK
PLLCK
pit_irq
MCK
proc_nreset
wdt_irq
periph_irq{2-3]
periph_nreset
periph_clk[2..18]
PCK
MCK
pmc_irq
UDPCK
nirq
nfiq
rtt_irq
Embedded
Peripherals
periph_clk[2-3]
pck[0-3]
in
out
enable
ARM7TDMI
SLCK
SLCK
irq0-irq1
fiq
irq0-irq1
fiq
periph_irq[4..19]
periph_irq[2..19]
int
int
periph_nreset
periph_clk[4..19]
Embedded
Flash
flash_poe
jtag_nreset
flash_poe
gpnvm[0..2]
flash_wrdis
flash_wrdis
proc_nreset
periph_nreset
dbgu_txd
dbgu_rxd
pit_irq
rtt_irq
dbgu_irq
pmc_irq
rstc_irq
wdt_irq
rstc_irq
efc_irq
SLCK
gpnvm[1]
Boundary Scan
TAP Controller
jtag_nreset
ice_nreset
debug
PCK
debug
idle
debug
Memory
Controller
MCK
proc_nreset
bod_rst_en
proc_nreset
periph_nreset
periph_nreset
idle
Debug
Unit
dbgu_irq
MCK
dbgu_rxd
periph_nreset force_ntrst
dbgu_txd
USB Device
Port
UDPCK
periph_nreset
periph_clk[11]
periph_irq[11]
usb_suspend
usb_suspend
Voltage
Regulator
standby
Voltage
Regulator
Mode
Controller
security_bit
cal
ice_nreset
force_ntrst
cal
PB0-PB30
efc_irq