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Chapter 12 Modulo Timer (S08MTIMV1)
MC9S08SH32 Series Data Sheet, Rev. 2
188
Freescale Semiconductor
12.3.1
MTIM Status and Control Register (MTIMSC)
MTIMSC contains the overow status ag and control bits which are used to congure the interrupt
enable, reset the counter, and stop the counter.
7
654
3
210
R
TOF
TOIE
0
TSTP
0
000
W
TRST
Reset:
0
1
0
Figure 12-4. MTIM Status and Control Register
Table 12-2. MTIM Status and Control Register Field Descriptions
Field
Description
7
TOF
MTIM Overow Flag — This read-only bit is set when the MTIM counter register overows to $00 after reaching
the value in the MTIM modulo register. Clear TOF by reading the MTIMSC register while TOF is set, then writing
a 0 to TOF. TOF is also cleared when TRST is written to a 1 or when any value is written to the MTIMMOD register.
0 MTIM counter has not reached the overow value in the MTIM modulo register.
1 MTIM counter has reached the overow value in the MTIM modulo register.
6
TOIE
MTIM Overow Interrupt Enable — This read/write bit enables MTIM overow interrupts. If TOIE is set, then an
interrupt is generated when TOF = 1. Reset clears TOIE. Do not set TOIE if TOF = 1. Clear TOF rst, then set TOIE.
0 TOF interrupts are disabled. Use software polling.
1 TOF interrupts are enabled.
5
TRST
MTIM Counter Reset — When a 1 is written to this write-only bit, the MTIM counter register resets to $00 and TOF
is cleared. Reading this bit always returns 0.
0 No effect. MTIM counter remains at current state.
1 MTIM counter is reset to $00.
4
TSTP
MTIM Counter Stop — When set, this read/write bit stops the MTIM counter at its current value. Counting resumes
from the current value when TSTP is cleared. Reset sets TSTP to prevent the MTIM from counting.
0 MTIM counter is active.
1 MTIM counter is stopped.
3:0
Unused register bits, always read 0.
PRELIMINARY