st10f273m STMicroelectronics, st10f273m Datasheet - Page 65

• Manufacturer Part Number: st10f273m
• Description: 16-bit Mcu With 512 Kbyte Flash Memory And 36 Kbyte Ram
• Manufacturer: STMicroelectronics

ST10F273M
11.2
Table 36.
Prescaler factor
Input frequency
Resolution
Period maximum
f
CPU
= 40 MHz
GPT2
The GPT2 module provides precise event control and time measurement. It includes two
timers (T5, T6) and a capture/reload register (CAPREL). Both timers can be clocked with an
input clock which is derived from the CPU clock via a programmable prescaler or with
external signals. The count direction (up/down) for each timer is programmable by software
or may additionally be altered dynamically by an external signal on a port pin (TxEUD).
Concatenation of the timers is supported via the output toggle latch (T6OTL) of timer T6
which changes its state on each timer overflow/underflow.
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
40 MHz CPU clock.
GPT2 timer input frequencies, resolutions and periods at 40 MHz
10 MHz
6.55ms
100ns
000b
4
lists the timer input frequencies, resolution and periods for each prescaler option at
13.1ms
5 MHz
200ns
001b
8
2.5 MHz
26.2ms
400ns
010b
16
Timer Input Selection T5I / T6I
1.25 MHz
52.4ms
0.8µs
011b
32
104.8ms
625 kHz
1.6µs
100b
64
312.5 kHz 156.25 kHz 78.125 kHz
209.7ms
3.2µs
101b
128
General purpose timer unit
419.4ms
6.4µs
110b
256
838.9ms
12.8µs
111b
512
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