Chapter 15 Timer Module (TIM16B8CV1) Block Description
Freescale Semiconductor
MC9S12C-Family / MC9S12GC-Family
457
Rev 01.24
15.3.2.17 Pulse Accumulators Count Registers (PACNT)
Read: Anytime
Write: Anytime
These registers contain the number of active input edges on its input pin since the last reset.
When PACNT overflows from 0xFFFF to 0x0000, the Interrupt flag PAOVF in PAFLG (0x0021) is set.
Full count register access should take place in one clock cycle. A separate read/write for high byte and low
byte will give a different result than accessing them as a word.
NOTE
Reading the pulse accumulator counter registers immediately after an active
edge on the pulse accumulator input pin may miss the last count because the
input has to be synchronized with the bus clock first.
15.4
Functional Description
This section provides a complete functional description of the timer TIM16B8CV1 block. Please refer to
the detailed timer block diagram in
Module Base + 0x0022
15
14
13
12
11
10
9
0
R
PACNT15
PACNT14
PACNT13
PACNT12
PACNT11
PACNT10
PACNT9
PACNT8
W
Reset
0
0
0
0
0
0
0
0
Figure 15-26. Pulse Accumulator Count Register High (PACNTH)
Module Base + 0x0023
7
6
5
4
3
2
1
0
R
PACNT7
PACNT6
PACNT5
PACNT4
PACNT3
PACNT2
PACNT1
PACNT0
W
Reset
0
0
0
0
0
0
0
0
Figure 15-27. Pulse Accumulator Count Register Low (PACNTL)
Summary of Contents for MC9S12C Family
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