Datasheet

Enhanced Capture Timer
Timer Register Descriptions
MC68HC912DT128A — Rev 4.0 Technical Data
MOTOROLA Enhanced Capture Timer 253
When the OC7Mn bit is set, a successful OC7 action will override a
successful OC[6:0] compare action during the same cycle; therefore, the
OCn action taken will depend on the corresponding OC7D bit.
The 16-bit main timer is an up counter.
A full access for the counter register should take place in one clock cycle.
A separate read/write for high byte and low byte will give a different result
than accessing them as a word.
Read anytime.
Write has no meaning or effect in the normal mode; only writable in
special modes (SMODN = 0).
The period of the first count after a write to the TCNT registers may be a
different size because the write is not synchronized with the prescaler
clock.
Read or write anytime.
TEN — Timer Enable
0 = Disables the main timer, including the counter. Can be used for
reducing power consumption.
1 = Allows the timer to function normally.
If for any reason the timer is not active, there is no ÷64 clock for the
pulse accumulator since the E÷64 is generated by the timer prescaler.
TCNT — Timer Count Register $0084–$0085
Bit 7 6 5 4 3 2 1 Bit 0
Bit 15 14 13 12 11 10 9 Bit 8
Bit 7 6 5 4 3 2 1 Bit 0
RESET: 0 0 0 0 0 0 0 0
TSCR — Timer System Control Register $0086
Bit 7 6 5 4 3 2 1 Bit 0
TEN TSWAI TSBCK TFFCA
RESET: 0 0 0 0 0 0 0 0
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cale Semiconductor,
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