Timer Module (TIM16B8CV2) Block Description
MC9S12XHY-Family Reference Manual, Rev. 1.01
538
Freescale Semiconductor
NOTE
If the timer is not active (TEN = 0 in TSCR), there is no divide-by-64
because the
÷
64 clock is generated by the timer prescaler.
For the description of PACLK please refer
Figure 16-30
.
If the pulse accumulator is disabled (PAEN = 0), the prescaler clock from the timer is always used as an
input clock to the timer counter. The change from one selected clock to the other happens immediately
after these bits are written.
16.3.2.16 Pulse Accumulator Flag Register (PAFLG)
Read: Anytime
Write: Anytime
When the TFFCA bit in the TSCR register is set, any access to the PACNT register will clear all the flags
in the PAFLG register. Timer module or Pulse Accumulator must stay enabled (TEN=1 or PAEN=1) while
clearing these bits.
Table 16-19. Pin Action
PAMOD
PEDGE
Pin Action
0
0
Falling edge
0
1
Rising edge
1
0
Div. by 64 clock enabled with pin high level
1
1
Div. by 64 clock enabled with pin low level
Table 16-20. Timer Clock Selection
CLK1
CLK0
Timer Clock
0
0
Use timer prescaler clock as timer counter clock
0
1
Use PACLK as input to timer counter clock
1
0
Use PACLK/256 as timer counter clock frequency
1
1
Use PACLK/65536 as timer counter clock frequency
Module Base + 0x0021
7
6
5
4
3
2
1
0
R
0
0
0
0
0
0
PAOVF
PAIF
W
Reset
0
0
0
0
0
0
0
0
Unimplemented or Reserved
Figure 16-25. Pulse Accumulator Flag Register (PAFLG)
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