s908az32ag2cfue Freescale Semiconductor, Inc, s908az32ag2cfue Datasheet - Page 198

• Manufacturer Part Number: s908az32ag2cfue
• Description: M68hc08 Microcontrollers 8-bit Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

Timer Interface Module A (TIMA)
TSTOP — TIMA Stop Bit
TRST — TIMA Reset Bit
PS[2:0] — Prescaler Select Bits
198
This read/write bit stops the TIMA counter. Counting resumes when TSTOP is cleared. Reset sets the
TSTOP bit, stopping the TIMA counter until software clears the TSTOP bit.
Setting this write-only bit resets the TIMA counter and the TIMA prescaler. Setting TRST has no effect
on any other registers. Counting resumes from $0000. TRST is cleared automatically after the TIMA
counter is reset and always reads as logic 0. Reset clears the TRST bit.
These read/write bits select either the PTD6/ATD14/TCLK pin or one of the seven prescaler outputs
as the input to the TIMA counter as
1 = TIMA counter stopped
0 = TIMA counter active
1 = Prescaler and TIMA counter cleared
0 = No effect
Do not set the TSTOP bit before entering wait mode if the TIMA is required
to exit wait mode. Also, when the TSTOP bit is set and input capture mode
is enabled, input captures are inhibited until TSTOP is cleared.
When using TSTOP to stop the timer counter, see if any timer flags are set.
If a timer flag is set, it must be cleared by clearing TSTOP, then clearing the
flag, then setting TSTOP again.
Setting the TSTOP and TRST bits simultaneously stops the TIMA counter
at a value of $0000.
PS[2:0]
000
001
010
011
100
101
110
111
Table 18-1. Prescaler Selection
MC68HC908AZ32A Data Sheet, Rev. 2
Table 18-1
NOTE
NOTE
shows. Reset clears the PS[2:0] bits.
Internal Bus Clock ÷ 16
Internal Bus Clock ÷ 32
Internal Bus Clock ÷ 64
Internal Bus Clock ÷ 2
Internal Bus Clock ÷ 4
Internal Bus Clock ÷ 8
Internal Bus Clock ÷1
TIMA Clock Source
PTD6/ATD14/TCLK
Freescale Semiconductor