MC908AS60ACFU Datasheet, PDF (317/414 Pages) Freescale Semiconductor, Inc – M68HC08 Microcontrollers

I/O Registers
25.8 I/O Registers
These I/O registers control and monitor TIMA operation:
• TIMA status and control register (TASC)
• TIMA control registers (TACNTH–TACNTL)
• TIMA counter modulo registers (TAMODH–TAMODL)
• TIMA channel status and control registers (TASC0, TASC1, TASC2, TASC3, TASC4 and TASC5)
• TIMA channel registers (TACH0H–TACH0L, TACH1H–TACH1L, TACH2H–TACH2L,
TACH3H–TACH3L, TACH4H–TACH4L and TACH5H–TACH5L)
25.8.1 TIMA Status and Control Register
The TIMA status and control register:
• Enables TIMA overflow interrupts
• Flags TIMA overflows
• Stops the TIMA counter
• Resets the TIMA counter
• Prescales the TIMA counter clock
Address: $0020
Bit 7
6
5
4
3
2
1
Bit 0
Read: TOF
0
0
TOIE TSTOP
Write: 0
TRST
R
PS2
PS1
PS0
Reset: 0
0
1
0
0
0
0
0
R
= Reserved
Figure 25-4. TIMA Status and Control Register (TASC)
TOF — TIMA Overflow Flag Bit
This read/write flag is set when the TIMA counter reaches the modulo value programmed in the TIMA
counter modulo registers. Clear TOF by reading the TIMA status and control register when TOF is set
and then writing a logic 0 to TOF. If another TIMA overflow occurs before the clearing sequence is
complete, then writing logic 0 to TOF has no effect. Therefore, a TOF interrupt request cannot be lost
due to inadvertent clearing of TOF. Reset clears the TOF bit. Writing a logic 1 to TOF has no effect.
1 = TIMA counter has reached modulo value.
0 = TIMA counter has not reached modulo value.
TOIE — TIMA Overflow Interrupt Enable Bit
This read/write bit enables TIMA overflow interrupts when the TOF bit becomes set. Reset clears the
TOIE bit.
1 = TIMA overflow interrupts enabled
0 = TIMA overflow interrupts disabled
TSTOP — TIMA Stop Bit
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.
1 = TIMA counter stopped
0 = TIMA counter active
MC68HC908AZ60A • MC68HC908AS60A • MC68HC908AS60E Data Sheet, Rev. 6
Freescale Semiconductor
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