
XC161 Derivatives
Peripheral Units (Vol. 2 of 2)
The General Purpose Timer Units
User’s Manual
14-51
V2.2, 2004-01
GPT_X1, V2.0
lists a timer’s parameters (such as count frequency, resolution, and period)
resulting from the selected overall prescaler factor and the applied system frequency.
Note that some numbers may be rounded.
Table 14-15 GPT2 Overall Prescaler Factors for Internal Count Clock
Individual
Prescaler for Tx
Common Prescaler for Module Clock
1)
BPS2 = 01
B
BPS2 = 00
B
BPS2 = 11
B
BPS2 = 10
B
TxI = 000
B
2
4
8
16
TxI = 001
B
4
8
16
32
TxI = 010
B
8
16
32
64
TxI = 011
B
16
32
64
128
TxI = 100
B
32
64
128
256
TxI = 101
B
64
128
256
512
TxI = 110
B
128
256
512
1024
TxI = 111
B
256
512
1024
2048
1) Please note the non-linear encoding of bitfield BPS2.
Table 14-16 GPT2 Timer Parameters
System Clock = 10 MHz
Overall
Divider
Factor
System Clock = 40 MHz
Frequency
Resolution Period
Frequency
Resolution Period
5.0 MHz
200 ns
13.11 ms
2
20.0 MHz
50 ns
3.28 ms
2.5 MHz
400 ns
26.21 ms
4
10.0 MHz
100 ns
6.55 ms
1.25 MHz
800 ns
52.43 ms
8
5.0 MHz
200 ns
13.11 ms
625.0 kHz
1.6
µ
s
104.9 ms
16
2.5 MHz
400 ns
26.21 ms
312.5 kHz
3.2
µ
s
209.7 ms
32
1.25 MHz
800 ns
52.43 ms
156.25 kHz
6.4
µ
s
419.4 ms
64
625.0 kHz
1.6
µ
s
104.9 ms
78.125 kHz
12.8
µ
s
838.9 ms
128
312.5 kHz
3.2
µ
s
209.7 ms
39.06 kHz
25.6
µ
s
1.678 s
256
156.25 kHz
6.4
µ
s
419.4 ms
19.53 kHz
51.2
µ
s
3.355 s
512
78.125 kHz
12.8
µ
s
838.9 ms
9.77 kHz
102.4
µ
s
6.711 s
1024
39.06 kHz
25.6
µ
s
1.678 s
4.88 kHz
204.8
µ
s
13.42 s
2048
19.53 kHz
51.2
µ
s
3.355 s