mc9s12q128 Freescale Semiconductor, Inc, mc9s12q128 Datasheet - Page 450

• Manufacturer Part Number: mc9s12q128
• Description: Hcs12 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

Chapter 15 Timer Module (TIM16B6C) Block Description
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.
450
Module Base + 0x0022
Module Base + 0x0023
Reset
Reset
W
W
R
R
PACNT15
PACNT7
15
0
0
7
edge on the pulse accumulator input pin may miss the last count because the
input has to be synchronized with the bus clock first.
Reading the pulse accumulator counter registers immediately after an active
Figure 15-26. Pulse Accumulator Count Register High (PACNTH)
Figure 15-27. Pulse Accumulator Count Register Low (PACNTL)
PACNT14
PACNT6
14
0
0
6
PACNT13
PACNT5
13
0
0
5
PACNT12
MC9S12Q128
PACNT4
Rev 1.09
NOTE
12
0
0
4
PACNT11
PACNT3
11
0
0
3
PACNT10
PACNT2
10
0
0
2
PACNT9
PACNT1
Freescale Semiconductor
0
0
9
1
PACNT8
PACNT0
0
0
0
0