XC2287 / XC2286 / XC2285
XC2000 Family Derivatives
Preliminary
Functional Description
3.6
Capture/Compare Unit (CAPCOM2)
The CAPCOM2 unit supports generation and control of timing sequences on up to
16 channels with a maximum resolution of 1 system clock cycle (8 cycles in staggered
mode). The CAPCOM2 unit is typically used to handle high speed I/O tasks such as
pulse and waveform generation, pulse width modulation (PWM), Digital to Analog (D/A)
conversion, software timing, or time recording relative to external events.
Two 16-bit timers (T7/T8) with reload registers provide two independent time bases for
the capture/compare register array.
The input clock for the timers is programmable to several prescaled values of the internal
system clock, or may be derived from an overflow/underflow of timer T6 in module GPT2.
This provides a wide range of variation for the timer period and resolution and allows
precise adjustments to the application specific requirements. In addition, an external
count input for CAPCOM2 timer T7 allows event scheduling for the capture/compare
registers relative to external events.
The capture/compare register array contains 16 dual purpose capture/compare
registers, each of which may be individually allocated to either CAPCOM2 timer T7 or T8
and programmed for capture or compare function.
All registers of the CAPCOM2 module have each one port pin associated with it which
serves as an input pin for triggering the capture function, or as an output pin to indicate
the occurrence of a compare event.
Table 6
Compare Modes (CAPCOM2)
Compare Modes
Function
Mode 0
Interrupt-only compare mode;
Several compare interrupts per timer period are possible
Mode 1
Mode 2
Mode 3
Pin toggles on each compare match;
Several compare events per timer period are possible
Interrupt-only compare mode;
Only one compare interrupt per timer period is generated
Pin set ‘1’ on match; pin reset ‘0’ on compare timer overflow;
Only one compare event per timer period is generated
Double Register
Mode
Two registers operate on one pin;
Pin toggles on each compare match;
Several compare events per timer period are possible
Single Event Mode
Generates single edges or pulses;
Can be used with any compare mode
When a capture/compare register has been selected for capture mode, the current
contents of the allocated timer will be latched (‘captured’) into the capture/compare
Data Sheet
48
V0.91, 2007-02
Draft Version
INFINEON [ Infineon ]
