SAF-C164SM Infineon Technologies, SAF-C164SM Datasheet - Page 272

• Manufacturer Part Number: SAF-C164SM
• Description: 16-Bit CMOS Microcontroller
• Manufacturer: Infineon Technologies

C164CM/C164SM
Derivatives
Capture/Compare Unit CAPCOM2
Timer Mode
The bits TxM in SFR T78CON select between timer mode or counter mode for the
respective timer. In timer mode (TxM = ‘0’), the input clock for a timer is derived from the
internal CPU clock divided by a programmable prescaler. The different options for the
prescaler are selected separately for each timer by the bit fields TxI.
f
The input frequencies
for Tx are determined as a function of the CPU clock as
Tx
follows, where <TxI> represents the contents of the bit field TxI:
f
CPU
f
=
Tx
(<TxI> + 3)
2
When a timer overflows from FFFF
to 0000
, it is reloaded with the value stored in its
H
H
respective reload register TxREL. The reload value determines the period P
between
Tx
two consecutive overflows of Tx as follows:
16
(<TxI> + 3)
(2
- <TxREL>)
2
P
=
Tx
f
CPU
After a timer has been started by setting its run flag (TxR) to ‘1’, the first increment will
occur within the time interval defined by the selected timer resolution. All further
increments occur exactly after the time defined by the timer resolution.
When both timers of the CAPCOM2 unit are to be incremented or reloaded at the same
time, T7 is always serviced one CPU clock before T8.
The timer input frequencies, resolution and periods which result from the selected
prescaler option in TxI when using a certain CPU clock are listed in
Table 16-2
-
Table
16-4. The numbers for the timer periods are based on a reload value of 0000
.
H
Note that some numbers may be rounded to 3 significant digits.
User’s Manual
16-6
V1.0, 2002-02