MC908QL4 FREESCALE [Freescale Semiconductor, Inc], MC908QL4 Datasheet - Page 180

• Manufacturer Part Number: MC908QL4
• Description: M68HC08 Microcontrollers
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

Timer Interface Module (TIM)
15.7.1 TIM Channel I/O Pins (TCH1:TCH0)
Each channel I/O pin is programmable independently as an input capture pin or an output compare pin.
TCH0
15.7.2 TIM Clock Pin (TCLK)
TCLK is an external clock input that can be the clock source for the counter instead of the prescaled
internal bus clock. Select the TCLK input by writing 1s to the three prescaler select bits, PS[2:0]. The
minimum TCLK pulse width is specified in the Timer Interface Module Characteristics table in the
Electricals section. The maximum TCLK frequency is the least of 4 MHz or bus frequency ÷ 2.
15.8 Registers
The following registers control and monitor operation of the TIM:
15.8.1 TIM Status and Control Register
The TIM status and control register (TSC) does the following:
TOF — TIM Overflow Flag Bit
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This read/write flag is set when the counter reaches the modulo value programmed in the TIM counter
modulo registers. Clear TOF by reading the TSC register when TOF is set and then writing a 0 to TOF.
If another TIM overflow occurs before the clearing sequence is complete, then writing 0 to TOF has no
effect. Therefore, a TOF interrupt request cannot be lost due to inadvertent clearing of TOF. Writing a
1 to TOF has no effect.
1 = Counter has reached modulo value
0 = Counter has not reached modulo value
can be configured as buffered output compare or buffered PWM pin.
TIM status and control register (TSC)
TIM control registers (TCNTH:TCNTL)
TIM counter modulo registers (TMODH:TMODL)
TIM channel status and control registers (TSC0 and TSC1)
TIM channel registers (TCH0H:TCH0L and TCH1H:TCH1L)
Enables TIM overflow interrupts
Flags TIM overflows
Stops the counter
Resets the counter
Prescales the counter clock
Reset:
Read:
Write:
Bit 7
TOF
0
0
Figure 15-4. TIM Status and Control Register (TSC)
= Unimplemented
TOIE
6
0
MC68HC908QL4 Data Sheet, Rev. 7
TSTOP
5
1
TRST
4
0
0
3
0
0
PS2
2
0
PS1
1
0
Freescale Semiconductor
Bit 0
PS0
0