SAB80C166-M-T3 SIEMENS [Siemens Semiconductor Group], SAB80C166-M-T3 Datasheet - Page 16

• Manufacturer Part Number: SAB80C166-M-T3
• Description: 16-Bit CMOS Single-Chip Microcontroller
• Manufacturer: SIEMENS [Siemens Semiconductor Group]

Capture/Compare (CAPCOM) Unit
The CAPCOM unit supports generation and control of timing sequences on up to 16 channels with
a maximum resolution of 400 ns (@ 20 MHz CPU clock). The CAPCOM unit is typically used to
handle high speed I/O tasks such as pulse and waveform generation, pulse width modulation
(PMW), Digital to Analog (D/A) conversion, software timing, or time recording relative to external
events.
Two 16-bit timers (T0/T1) 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 CPU 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 CAPCOM timer T0 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 CAPCOM timer T0 or T1, and programmed for capture
or compare function. Each register has 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.
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 register in response to an
external event at the port pin which is associated with this register. In addition, a specific interrupt
request for this capture/compare register is generated. Either a positive, a negative, or both a
positive and a negative external signal transition at the pin can be selected as the triggering event.
The contents of all registers which have been selected for one of the five compare modes are
continuously compared with the contents of the allocated timers. When a match occurs between the
timer value and the value in a capture/compare register, specific actions will be taken based on the
selected compare mode.
Compare Modes
Mode 0
Mode 1
Mode 2
Mode 3
Double
Register Mode
Semiconductor Group
Function
Interrupt-only compare mode;
several compare interrupts per timer period are possible
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 time overflow;
only one compare event per timer period is generated
Two registers operate on one pin; pin toggles on each compare match;
several compare events per timer period are possible.
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SAB 80C166/83C166