Timer Interface B (TIMB)
MC68HC908MR32 • MC68HC908MR16 Data Sheet, Rev. 6.1
244 Freescale Semiconductor
17.7 I/O Registers
These input/output (I/O) registers control and monitor TIMB operation:
TIMB status and control register (TBSC)
TIMB control registers (TBCNTH–TBCNTL)
TIMB counter modulo registers (TBMODH–TBMODL)
TIMB channel status and control registers (TBSC0 and TBSC1)
TIMB channel registers (TBCH0H–TBCH0L and TBCH1H–TBCH1L)

17.7.1 TIMB Status and Control Register

The TIMB status and control register:
Enables TIMB overflow interrupts
Flags TIMB overflows
Stops the TIMB counter
Resets the TIMB counter
Prescales the TIMB counter clock
TOF — TIMB Overflow Flag
This read/write flag is set when the TIMB counter reaches the modulo value programmed in the TIMB
counter modulo registers. Clear TOF by reading the TIMB status and control register when TOF is set
and then writing a logic 0 to TOF. If another TIMB 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 = TIMB counter has reached modulo value.
0 = TIMB counter has not reached modulo value.
TOIE — TIMB Overflow Interrupt Enable Bit
This read/write bit enables TIMB overflow interrupts when the TOF bit becomes set. Reset clears the
TOIE bit.
1 = TIMB overflow interrupts enabled
0 = TIMB overflow interrupts disabled
Address: $0051
Bit 7654321Bit 0
Read: TOF
TOIE TSTOP
00
PS2 PS1 PS0
Write: 0 TRST R
Reset:00100000
R= Reserved
Figure 17-5. TIMB Status and Control Register (TBSC)