ST10F271 Datasheet, PDF (60/173 Pages) STMicroelectronics – 16-bit MCU with 128 Kbyte Flash memory and 12 Kbyte RAM

General purpose timer unit
ST10F271
The state of this latch may be used to clock timer T5, or it may be output on a port pin
(T6OUT). The overflow / underflow of timer T6 can additionally be used to clock the
CAPCOM timers T0 or T1, and to cause a reload from the CAPREL register. The CAPREL
register may capture the contents of timer T5 based on an external signal transition on the
corresponding port pin (CAPIN), and timer T5 may optionally be cleared after the capture
procedure. This allows absolute time differences to be measured or pulse multiplication to
be performed without software overhead.
The capture trigger (timer T5 to CAPREL) may also be generated upon transitions of GPT1
timer T3 inputs T3IN and/or T3EUD. This is advantageous when T3 operates in Incremental
Interface Mode.
Table 36 and Table 37 list the timer input frequencies, resolution and periods for each pre-
scaler option at 40MHz and 64MHz CPU clock respectively.
Table 36. GPT2 timer input frequencies, resolutions and periods at 40 MHz
f_CPU = 40MHz
000b
001b
Timer Input Selection T5I / T6I
010b 011b 100b 101b
110b
111b
Pre-scaler
factor
Input Freq
Resolution
Period
maximum
4
8
16
32
64
128
256
512
10MHz 5MHz 2.5MHz
100ns 200ns 400ns
1.25
MHz
0.8µs
625 kHz
1.6µs
312.5
kHz
3.2µs
156.25
kHz
6.4µs
78.125
kHz
12.8µs
6.55ms 13.1ms 26.2ms 52.4ms 104.8ms 209.7ms 419.4ms 838.9ms
Table 37. GPT2 timer input frequencies, resolutions and periods at 64 MHz
f_CPU = 64MHz
000b
001b
Timer Input Selection T5I / T6I
010b 011b 100b 101b
110b
111b
Pre-scaler
factor
Input Freq
Resolution
Period
maximum
4
8
16
32
64
128
256
512
16MHz 8MHz
62.5ns 125ns
4MHz
250ns
2MHz
0.5µs
1 kHz 500 kHz 250 kHz 128 kHz
1.0µs 2.0µs 4.0µs 8.0µs
4.1ms 8.2ms 16.4ms 32.8ms 65.5ms 131.1ms 262.1ms 524.3ms
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