MC68HC08AZ32A Datasheet, PDF (289/456 Pages) Motorola, Inc – HCMOS Microcontroller Unit

Freescale Semiconductor, Inc.
Programmable Interrupt Timer (PIT)
I/O Registers
NOTE: Do not set the PSTOP bit before entering wait mode if the PIT is required
to exit wait mode.
PRST — PIT Reset Bit
Setting this write-only bit resets the PIT counter and the PIT prescaler.
Setting PRST has no effect on any other registers. Counting resumes
from $0000. PRST is cleared automatically after the PIT counter is
reset and always reads as logic zero. Reset clears the PRST bit.
1 = Prescaler and PIT counter cleared
0 = No effect
NOTE: Setting the PSTOP and PRST bits simultaneously stops the PIT counter
at a value of $0000.
PPS[2:0] — Prescaler Select Bits
These read/write bits select one of the seven prescaler outputs as the
input to the PIT counter as Table 18-2 shows. Reset clears the
PPS[2:0] bits.
PPS[2:0]
000
001
010
011
100
101
110
111
Table 18-2. Prescaler Selection
PIT Clock Source
Internal Bus Clock ÷1
Internal Bus Clock ÷ 2
Internal Bus Clock ÷ 4
Internal Bus Clock ÷ 8
Internal Bus Clock ÷ 16
Internal Bus Clock ÷ 32
Internal Bus Clock ÷ 64
Internal Bus Clock ÷ 64
MC68HC08AZ32A — Rev 1.0
MOTOROLA
Programmable Interrupt Timer (PIT)
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Technical Data
289