Infineon Technologies XMC4000 Application Kit User manual

Microcontroller
XMC4000
XMC4500 Family
User Guide
Device Guide
<Revision 1.0>, <2012-30-03>
Capture Compare Unit - CCU4
CCU Basics

Edition <2012-30-03>
Published by
Infineon Technologies AG
81726 Munich, Germany
© 2012 Infineon Technologies AG
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Device Guide XMC4500
Capture Compare Unit - CCU4
Confidential
Revision History
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<Revision 1.0>, <2012-30-03>
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Device Guide XMC4500
Capture Compare Unit - CCU4
Confidential List of Tables
Table of Contents
1CCU Basics.........................................................................................................................................6
1.1 Basic Timer Functions..........................................................................................................................7
1.1.1The Compound CAPCOM4 System CCU40 –CCU43........................................................................7
1.2 CCU Use Cases...................................................................................................................................9
1.3 Typical Use Case Features of the CAPCOM4/8..................................................................................9
2Additional CCU Features.................................................................................................................10
2.1 Single Shot.........................................................................................................................................10
2.2 Timer Concatenation..........................................................................................................................10
2.3 Dithering PWM...................................................................................................................................10
2.4 Dithering Period Time ........................................................................................................................10
2.5 Floating Prescaler ..............................................................................................................................10
2.6 External Modulation ...........................................................................................................................10
2.7 Output State Override ........................................................................................................................10
2.8 Multi Channel Control.........................................................................................................................10
2.8.1 Multi Channel Use Case ....................................................................................................................11
2.9 Timer Load Function ..........................................................................................................................11
2.10 Trap Function.....................................................................................................................................11
2.11 Asymmetric Compare.........................................................................................................................11
3CCU4 Input Control..........................................................................................................................11
3.1 Synchronized Control of CAPCOM Units on External Events ...........................................................11
3.2 External Control Basics......................................................................................................................11
3.3 External Events Control .....................................................................................................................11
3.4 External Events Sources....................................................................................................................12
3.5 External Events Input Functions ........................................................................................................12
3.5.1 Extended Input Functions ..................................................................................................................12
4Capture Basics .................................................................................................................................12
5CCU4 Output Control.......................................................................................................................13
5.1 External Control by Timer Events ......................................................................................................13
5.2 Top-Level Control of Event Requests to/from a Timer Slice..............................................................14
6Compare Basics...............................................................................................................................14
6.1.1 CCU4 Shadow Transfers ...................................................................................................................14
6.1.2 Shadow Transfer of Compare Register values..................................................................................14
6.2 Asymmetric Compare Events.............................................................................................................15
6.3 Shadow Transfers in General - Compound Shadow Transfers.........................................................16
6.4 CCU4 Output State and Output Pin PASSIVE / ACTIVE Level Control............................................16
7How to Start a Timer ........................................................................................................................16
7.1 CAPCOM4 Ultimate Initialization Sequence......................................................................................16
7.2 Ultimate Start-Up Enable ...................................................................................................................16
7.3 Start Timer Running...........................................................................................................................16
7.4 Global Start of CAPCOM Units ..........................................................................................................17
7.5 Global Start of the CAPCOM Units CCU4 and CCU8 .......................................................................17
8Getting Started with Capture Compare Unit - CCU4.....................................................................18
8.1 How to Start Timer CC4y (y=0-3).......................................................................................................18
8.1.1 Example 1: Start Timer by SW (by Instruction)..................................................................................18
8.2 Example 2: Start Timer by HW (by External Event)...........................................................................18
8.2.1 External Events Control Setup Registers...........................................................................................18
8.2.2 Using the External Start Control Register Bitfields ............................................................................18
8.2.3 Example 3: Start Timers Synchronized (by Global Command).........................................................18
9Runtime Handling of Capture Compare Unit –CCU4...................................................................19
9.1 Example: Handling Shadow Transfers...............................................................................................19

Device Guide XMC4500
Capture Compare Unit - CCU4
Confidential List of Tables
List of Figures
Figure 1 The Timer Slice Block Diagram............................................................................................................6
Figure 2 Basic Functions of each Timer Slice....................................................................................................7
Figure 3 The four Capture/Compare units CCU40-CCU43 basic system of CAPCOM4...................................8
Figure 5 Some Features and Use Cases (1 –9) characterizing an CAPCOM Unit (CCU) Features................9
Figure 8 External Control of Timer Input Functions on Events by any External Units.....................................12
Figure 9 Timer Slice four Capture Registers....................................................................................................13
Figure 10 Basic Capture Mechanism –setup in two possible scheme alternatives ..........................................13
Figure 11 Timer Slice Compare Registers and PWM related Blocks.................................................................14
Figure 12 Basic Shadow Transfer Mechanism for Compare Register Values...................................................15
Figure 13 Asymmetric Compare by Shadow Transfers on both Period Match and One Match ........................16
Figure 15 External Event Control with Global Start Command..........................................................................17
Figure 16 Compound Shadow Transfer Mechanism with Coherent Update of PWM........................................19

Device Guide XMC4500
Capture Compare Unit - CCU4
Confidential CCU Basics
1 CCU Basics
A CAPCOM Unit (CCU) is a multi purpose timer unit for many use cases. It is designed with repetitive structures
with multiple timer slices, which have all the same base functionalities. This allows the development of re-usable
software low level drivers. The specific features can be combined among each other and even with other
peripherals such as ADC. With this it is possible to generate any kind of pulses, trigger events or time captures
without CPU interaction. The main function blocks of 1 of the 4 equal timer slices on a CCU4x is shown here.
See Figure 1.
Figure 1 The Timer Slice Block Diagram

Device Guide XMC4500
Capture Compare Unit - CCU4
Confidential CCU Basics
1.1 Basic Timer Functions
Figure 2 Basic Functions of each Timer Slice
Each timer slice can handle all basic modes and typical options as illustrated here independently of another.
See Figure 2.
1.1.1 The Compound CAPCOM4 System CCU40 –CCU43
Each CCU4x (x=3-0), has four 16-bit timer slices CC4y (y=3-0), concatenatable up to 64-bit. A slice has 1
Timer, 4 Capture-, 1 Period- and 1 Compare register. The latter two have shadow registers for reload.
Slices may work independently in different modes - but may also be synchronized, even to other CCU4x slices.
They perform multi channel/multi phase pattern generation by update in parallel, on global request flag patterns.
See Figure 3.

Device Guide XMC4500
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Confidential CCU Basics
Figure 3 The four Capture/Compare units CCU40-CCU43 basic system of CAPCOM4

Device Guide XMC4500
Capture Compare Unit - CCU4
Confidential CCU Basics
1.2 CCU Use Cases
The various capabilities of the CAPCOM timer slices are illustrated here by typical use cases, shortly described.
See Figure 4.
Figure 5 Some Features and Use Cases (1 –9) characterizing an CAPCOM Unit (CCU) Features
1.3 Typical Use Case Features of the CAPCOM4/8
1. Simple Time Base with synchronization option by external events control
2. Power Conversion Systems (PFC, SMPS) using Single Shot Mode
3. Event Monitoring and Revolution by Capture, Count and Position Interface facilities (POSIF)
4. Multi Signal Pattern on Output Pins, created by parallel Multi Channel Control
5. Drive & Motor Control with Multi Phase Systems, Phase Adjustment and Trap Handling
6. 3-Level PWM for Inverters and Direct Torque Control (DTC) of AC Motors and High Precision Sync. Motors
7. External Events Control of Timer Input Functions by requests from external system units in interaction
8. Dithering PWM or Period for DC-Level precision, Reduced EMI, Fractional Split of Periods into Micro Steps

Device Guide XMC4500
Capture Compare Unit - CCU4
Confidential Additional CCU Features
9. Auto Adjusting Time Base by Floating Prescaler for adaption of time measurement to unknown dynamics
2 Additional CCU Features
2.1 Single Shot
A slice may be set in Timer Single Shot Mode (TSSM). Both the Timer and its Run Bit (TRB) is cleared by the
Period/One match that occurs next to when the TSSM bit was set - and thus the timer is stopped. A time frame,
e.g. a certain delay, is determined by the timer preset conditions and may start on any internal or external event.
2.2 Timer Concatenation
Any timer may be concatenated with an adjacent slice timer as easy as just by setting the respective TCE bits.
Thus you may get one or two 32-bit timers, one of 2 possible 48-bit timers or a whole 64-bit timer this way. The
first slice’s configuration is propagated throughout the rest and so a complete synchronization from LSB to MSB.
2.3 Dithering PWM
Dithering is an HW option in all the CAPCOM4 timers and may leverage PWM DC-level precision upto 16 times.
This special HW part may create a kind of superposed jitter upon a timer PWM output signal –to such an extent
that the affected PWM pattern DC-level (Vout) will converge to an average value with the targeted precision level.
2.4 Dithering Period Time
Micro Ticks can be used in the interpolation between e.g. the sensor pulses from a cog wheel, to achieve
position monitoring with higher precision. However, since the divisions of the sensor pulse period intervals
seldom become exact multiples of micro tick periods, dithering can optimize the distribution of ticks over time.
2.5 Floating Prescaler
By successive halving of the timer clock frequency periodically, as long there is no capture (or compare) event,
the dynamic range may be autonomously adapted to any time length, by using the slice’s floating prescaler. In
compare mode an arbitrary count range can be setup by using the floating prescaler compare value register too.
2.6 External Modulation
A slice may have its output pin modulated by external events. This function (and the active level of the event
source) should be mapped to one of the 3 inputs of the slice in the CC4yCMC and CC4yINS registers.
Modulation alternatives can be selected in CC4yTC for either Status Bit Clear or just Output Gating on events.
2.7 Output State Override
An input signal value (or its complement value) from one external source may override a slice’s status bit value
on an edge event by another external source. Both input sources are selected by the CC4yINS register - and
the specific function by the matrix control register CC4yCMC. Use cases are output timing control by monitoring.
2.8 Multi Channel Control
The output pin state of slices that are set in multi channel mode (by the CC4yTC.MCME bit) can be controlled in
parallel by a single pattern, according to the connected external signal on each CCU4xMCIy input. This task is
requested by the CCU4xMCSS input and synchronized with the update of the status bit and shadow transfers.

Device Guide XMC4500
Capture Compare Unit - CCU4
Confidential CCU4 Input Control
2.8.1 Multi Channel Use Case
The Position Interface module POSIF in conjunction with a CCU4x unit in multi channel mode enables complete
synchronicity between the output state update and the application of a new pattern. With POSIF in Hall Sensor
Mode, this can be used for direct control of brushless DC motors, to output the wanted motor control pattern.
2.9 Timer Load Function
An external source may trigger a Timer Reload transfer from either the compare register (if counting up) or from
the Period register (if counting down). The count direction bit CC4yTCST.CDIR can be set by SW or by another
external source. The input source(s) and function(s) should be mapped to the CC4yINS & CC4yCMC registers.
2.10 Trap Function
The trap function forces a PWM output into a predefined state, preset in the active/passive bit PSL. A power
device can be switched off safely this way. The input selection, trap and output functionality should be mapped
to the slice’s CC4yINS, CC4yCMC and CC4yPSL registers. Outputs are Trap-Enabled by the CC4yTC register.
2.11 Asymmetric Compare
Shadow transfers on both Period and One Match in center aligned mode enable asymmetric compare events.
(However, CAPCOM8 slices offer two compare registers per timer plus two corresponding shadow registers –
which circumstances simplify for example applications that require PWM Phase Shift Control facilities etc.)
3 CCU4 Input Control
3.1 Synchronized Control of CAPCOM Units on External Events
The manner of External Events Control distribution to CCUs (i.e. including CCU8 as well) opens for advanced
applications with synchronized timer control - e.g. in Drive & Power Control, such as 3-Level Inverters requiering
12 synchronized PWM. Just the fantacy may limit the realizable topography or timing pattern complexity range.
3.2 External Control Basics
A slice may have its input functions controlled by external sources. The external source(s),active mode(s) and
input function(s) should be mapped to the 3 inputs of the slice in the CC4yINS and CC4yCMC registers.
Function mode extending alternatives can be added by selections in the CC4yTC Timer Slice Control register.
3.3 External Events Control
An External Event Control request is a considered edge or level event signal from a peripheral unit or a GPIO. It
can be linked to CCU4xCC4y slices input selection stages via a comprehensive matrix. A slice that by any of its
3 events setups detects a considered source-event-input profile can be function controlled "remotely” this way!
See Figure 5.

Device Guide XMC4500
Capture Compare Unit - CCU4
Confidential Capture Basics
Figure 6 External Control of Timer Input Functions on Events by any External Units
3.4 External Events Sources
CCU4xCC4y Input Functions can be linked to external trigger requests –from such as the following sources:
GPIO, ERU, POSIF, CAN, CCU4x, USIC, ADC, CCU8x or SCU. Pin Connections are given by the Top-Level
Interconnect matrix and the CC4yINS[P:A] Input Select vector - and Function Select by the CC4yCMC register.
3.5 External Events Input Functions
There are 11 Timer Input Functions (as e.g. Start the Timer), controlable by external events via 3 selectable
input lines with configurable source-event profile conditions to the Timer Slices CC4y (y=0-3) of a CCU4x unit
(x=0-3) for Start, Stop, Capture0-3, Gate, Up/Down, Load, Count, Bit Override, Trap & Modulate Output control.
3.5.1 Extended Input Functions
There are some Extended Input Functions too, in the register CC4yTC for Extended Start,-Stop with Flush/Start,
Flush/Stop or Flush –or Extended Capture Mode as well, which together with a read access register (ECRD)
simplifies administration of capture registers and full-flags, when more than one slice is used in Capture mode.
4 Capture Basics
There are 4 CAPCOM4 (CCU4x) with 4 timer-slices each - and each slice has 4 capture value registers, split
into 2 pairs that will capture on selected event control input: Capt0 or Capt1 –according to 2 possible pair
schemes: either as 2 pairs for different events to Capt0 resp. Capt1 or cascaded for the same event via Capt1.

Device Guide XMC4500
Capture Compare Unit - CCU4
Confidential CCU4 Output Control
Figure 7 Timer Slice four Capture Registers
Figure 8 Basic Capture Mechanism –setup in two possible scheme alternatives
5 CCU4 Output Control
5.1 External Control by Timer Events
A timer event may trigger external actions via the Top-Level Interconnect matrix or request for an Interrupt.
Each CAPCOM4 has four Service Request Lines and each slice has a dedicated output signal CC4ySR[3...0]
selectable to a line by CC4ySRS. I.e. timer slice events may request for direct peripheral actions or an interrupt.

Device Guide XMC4500
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Confidential Compare Basics
5.2 Top-Level Control of Event Requests to/from a Timer Slice
Top-Level control means also conditional control of events requests between a slice and other action providers.
The Event Request Unit (ERU1) plus the Top-Level Interconnect matrix may combine, control and link event
signals according to user defined request-to-action event patterns - e.g. invoke I/O states, Time Windowing etc.
6 Compare Basics
Figure 9 Timer Slice Compare Registers and PWM related Blocks
6.1.1 CCU4 Shadow Transfers
All CAPCOM4 timers, in any slice configuration, no matter how complex or for what signal pattern, are assured
coherent update by HW of all concerned timer function parameters –by update values in shadow registers that,
on a global preset request, are transferred simultaneously to all function registers at a Period- or One-Match.
6.1.2 Shadow Transfer of Compare Register values
The compare values that are targeted for an update operation have to be written into the CC4yCRS shadow
registers - AND the corresponding Slice Transfer Set Enable bits, e.g. SySE in GCSS, must be preset –latest
within the clock cycle of Period Match (in Edge Aligned Mode) or Period/One Match (in Center Aligned Mode)

Device Guide XMC4500
Capture Compare Unit - CCU4
Confidential Compare Basics
Figure 10 Basic Shadow Transfer Mechanism for Compare Register Values
6.2 Asymmetric Compare Events
The benefit of shadow transfers on both Period Match and One Match, allows asymmetric compare events to be
provided in center aligned mode. The real time conditions are similar to handling shadow value updates in edge
aligned mode. An even stronger solution for this is offered by the CCU8 units by offering two shadow registers.

Device Guide XMC4500
Capture Compare Unit - CCU4
Confidential How to Start a Timer
Figure 11 Asymmetric Compare by Shadow Transfers on both Period Match and One Match
6.3 Shadow Transfers in General - Compound Shadow Transfers
Beside the Compare (CR) values, there are also the the timer Period register (PR) and the PWM Active/Passive
control bit (PSL) that may be updated simultaneously on the SySE flag. Dithering or Floating Prescaler values
(not shown here though) are able to get simultaneous update too by the SyDSE & SyPSE request flags.
6.4 CCU4 Output State and Output Pin PASSIVE / ACTIVE Level Control
The PASSIVE/ACTIVE state of a slice internal output CCUxSTy (i.e. status bit CC4yST)is controlled by the
compare level and the External Modulation Mode. Wether the external output pin state CCU4xOUTy (e.g. the
PWM) should be Passive Low / Active High or vice versa, is controlled by the CC4yPSL Passive/Active bit PSL.
7 How to Start a Timer
7.1 CAPCOM4 Ultimate Initialization Sequence
Before start and execution of a timer slice SW first time, the CAPCOM4 must have been initialized appropriately
according to a specific CAPCOM4 Initialization Sequence: 1. Apply Reset, 2. Release Reset, 3. Enable Clock,
4. Enable Prescaler Block, 5. Configure Global Control, 6. Configure Slice(s) Functions, Interrupts and Start-up.
7.2 Ultimate Start-Up Enable
In the last part of the ultimate CAPCOM4 Initialization Sequence the startup value(s) for a specific Compare
Channel Status of the Timer Slice(s) may be configured by the respective GCSS.SyTS bit. After that the default
IDLE mode has to be removed from the Timer Slice(s) in register GIDLC and Start or Global Start can be done!
7.3 Start Timer Running
There are two ways to start a timer, either directly by SW setting the Timer Run Bit Set (TRBS) - or indirectly by
HW when a considered event occurs in an external unit that may be selected for this, according to the Top-
Level Connection Matrix for External Events Control –by CAN, ADC, USIC, IO, CCU4/8, ERU1, POSIF etc.

Device Guide XMC4500
Capture Compare Unit - CCU4
Confidential How to Start a Timer
7.4 Global Start of CAPCOM Units
There is a way to get a synchronized start of CAPCOM Units, both CCU40/-41/-42,/-43 and CCU80/-81:
Global Start by SW, by the CCUx Global Start Control bits in the Global Start Control register CCUCON
Global Start by HW, indirectly, by External Events Control using the registers CC4yINS and CC4yCMC
7.5 Global Start of the CAPCOM Units CCU4 and CCU8
Global start of nearly any number of timers, independently of CAPCOM unit belonging, can be performed as
shown here. By this manner a synchronization of the timers will be achieved and all timings can be controlled in
parallel –such a output pattern generation of many different kinds.
See Figure 15.
Figure 12 External Event Control with Global Start Command

Device Guide XMC4500
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Confidential Getting Started with Capture Compare Unit - CCU4
8 Getting Started with Capture Compare Unit - CCU4
8.1 How to Start Timer CC4y (y=0-3)
In the following examples it is assumed that the CAPCOM4 Ultimate Initialization Sequence start is done before.
8.1.1 Example 1: Start Timer by SW (by Instruction)
CC40TCSET |= 0x00000001; // Start Timer CC40 directly by setting the TRBS bit = 1
8.2 Example 2: Start Timer by HW (by External Event)
8.2.1 External Events Control Setup Registers
The Input Selection register CC4yINS maps External-Event-Sources and Edge/Level Mode conditions to the
Event[2:0] Input Lines. In turn the Connection Matrix Control register CC4yCMC maps the three Event[2:0] Input
Lines to any of the 11 Input Functions. The Timer Control register CC4yTC enables different Mode Alternatives.
8.2.2 Using the External Start Control Register Bitfields
10.CC4yCMC.STRTS Input function Selection and Event Number (x=0-2) Input Line Selection bitfield
11.CC4yINS.<Event-x bitfields> Event Source EVxIS (CC4yINS[P:A]), Event Mode EVxEM or EVxLM bitfields
12.CC4yTC.<bitfields> Timer Mode selections e.g. Modes/Extended modes, Counting Schemes etc
Note:When using the index ‘x’ in event nomenclature, it should be understood as ‘Actual Event[2:0] Number ’.
Note:When using the index ‘x’ in CCU4x nomenclature, it should be understood as ‘Actual CCU4 Unit Number’.
Note:The Ultimate Event  Number ‘x’ for the STRTS Input Function is x == <STRTS>-1 (when <STRTS> != 0).
Note:If External Events Control of Up/Down Counting is used –then the counting scheme is always edge
aligned and the Timer Counting Mode bit (TCM) is read-only!
// Example 2:
// Assume a falling edge transition on GPIO Pin P1.3 as a “considered” external
// event control signal to start Timer CC40 in CAPCOM Unit CCU40.
// Define this event as “Event2”. (The alternatives Event0..1 would do as well!):
CC40CMC |= 0x00000003; // Start of Timer CC40 indirectly by External Event 2.
// Setup Timer CC40 External Event Control Input Selection register (CC40INS)
// to activate GPIO Pin P1.3 as selected source for Event 2 in the bitfield EV2S:
EV2S = 0; // where “0” is the input number (from 0-15) for the input “CCU40IN0[A]”
// and represents Pin P1.3 according to the Top-level Connection Matrix.
EV2EM = 2; // set signal active on falling edge on Event 2, as “considered”.
// See reference: Table 26-10 Pin Definition and I/O Functions
//
8.2.3 Example 3: Start Timers Synchronized (by Global Command)
// Start on Negative Edge on Port Pin P1.3 for CCU40IN0[A]
// See reference: Table 26-10 Pin Definition and I/O Functions

Device Guide XMC4500
Capture Compare Unit - CCU4
Confidential Runtime Handling of Capture Compare Unit –CCU4
9 Runtime Handling of Capture Compare Unit –CCU4
9.1 Example: Handling Shadow Transfers
Figure 13 Compound Shadow Transfer Mechanism with Coherent Update of PWM

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