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MC68HC05L28 Datasheet, PDF (64/156 Pages) Motorola, Inc – Flexible general-purpose microcomputer | |||
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When using the timer overï¬ow function and reading the free-running counter at random times to
measure an elapsed time, a problem may occur whereby the timer overï¬ow ï¬ag is unintentionally
cleared if:
â the timer status register is read or written when TOF is set and
â the LSB of the free-running counter is read, but not for the purpose of
servicing the ï¬ag.
Reading the alternate counter register instead of the counter register will avoid this potential
problem.
TCAP1 â Timer capture 1
This bit reï¬ects the current status of the timer capture 1 input.
Note: On the MC68HC05L28, TCAP1 is connected directly to PD0 which defaults to an input
6
with pull-up on reset. TCAP1 will be â1â unless PD0 is externally driven low.
TCAP2 â Timer capture 2
This bit reï¬ects the current state of the timer capture 2 Input.
Note:
On the MC68HC05L28, TCAP2 is connected directly to PD2 which defaults to an input
with pull-up on reset. TCAP2 will be â1â unless PD2 is externally driven low.
OC2F â Output compare 2 ï¬ag
1 (set) â A valid output compare has occurred.
0 (clear) â No output compare has occurred.
This bit is set when the output compare register contents match those of the free-running counter;
an output compare interrupt will be generated, if OC2IE is set. OC2F is cleared by reading the TSR
and then the output compare low 2 register at $27.
Bit 0 â always reads zero.
MOTOROLA
6-8
16-BIT PROGRAMMABLE TIMER
TPG
MC68HC05L28
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