MC9S12C Datasheet, PDF (454/680 Pages) Motorola, Inc – 16-Bit Microcontroller

Chapter 15 Timer Module (TIM16B8CV1) Block Description
CLK1
0
0
1
1
Table 15-19. Timer Clock Selection
CLK0
0
1
0
1
Timer Clock
Use timer prescaler clock as timer counter clock
Use PACLK as input to timer counter clock
Use PACLK/256 as timer counter clock frequency
Use PACLK/65536 as timer counter clock frequency
For the description of PACLK please refer Figure 15-24.
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.
15.3.2.16 Pulse Accumulator Flag Register (PAFLG)
Module Base + 0x0021
7
6
5
4
3
2
1
R
0
0
0
0
0
0
PAOVF
W
Reset
0
0
0
0
0
0
0
Unimplemented or Reserved
Figure 15-25. Pulse Accumulator Flag Register (PAFLG)
0
PAIF
0
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.
Table 15-20. PAFLG Field Descriptions
Field
1
PAOVF
0
PAIF
Description
Pulse Accumulator Overflow Flag — Set when the 16-bit pulse accumulator overflows from 0xFFFF to 0x0000.
This bit is cleared automatically by a write to the PAFLG register with bit 1 set.
Pulse Accumulator Input edge Flag — Set when the selected edge is detected at the IOC7 input pin.In event
mode the event edge triggers PAIF and in gated time accumulation mode the trailing edge of the gate signal at
the IOC7 input pin triggers PAIF.
This bit is cleared by a write to the PAFLG register with bit 0 set.
Any access to the PACNT register will clear all the flags in this register when TFFCA bit in register TSCR(0x0006)
is set.
454
MC9S12C-Family / MC9S12GC-Family
Freescale Semiconductor
Rev 01.23