Timer Interface (TIM)
Data Sheet
MC68HC08AS32A — Rev. 1
252
Timer Interface (TIM)
MOTOROLA
16.7.1 TIM Clock Pin (PTD6/ATD14/TCLK)
PTD6/ATD14/TCLK is an external clock input that can be the clock source for the
TIM counter instead of the prescaled internal bus clock. Select the
PTD6/ATD14/TCLK
input by writing logic 1s to the three prescaler select bits,
PS[2–0]. (See
16.8.1 TIM Status and Control Register
.) The minimum TCLK
pulse width is specified in
18.12 Timer Module Characteristics
. The maximum
TCLK frequency is the least: 4 MHz or bus frequency
÷
2.
PTD6/ATD14/TCLK is available as a general-purpose I/O pin or ADC channel
when not used as the TIM clock input. When the PTD6/ATD14/TCLK pin is the TIM
clock input, it is an input regardless of the state of the DDRD6 bit in data direction
register D.
16.7.2 TIM Channel I/O Pins (PTF3/TCH5–PTF0/TCH2 and PTE3/TCH1–PTE2/TCH0)
Each channel I/O pin is programmable independently as an input capture pin or an
output compare pin. PTE2/TCH0, PTE6/TCH2, and PTF2/TCH4 can be configured
as buffered output compare or buffered PWM pins.
16.8 I/O Registers
These I/O registers control and monitor TIM operation:
TIM status and control register (TSC)
TIM control registers (TCNTH–TCNTL)
TIM counter modulo registers (TMODH–TMODL)
TIM channel status and control registers (TSC0, TSC1, TSC2, TSC3, TSC4,
and TSC5)
TIM channel registers (TCH0H–TCH0L, TCH1H–TCH1L, TCH2H–TCH2L,
TCH3H–TCH3L, TCH4H–TCH4L, and TCH5H–TCH5L)
16.8.1 TIM Status and Control Register
The TIM status and control register:
Enables TIM overflow interrupts
Flags TIM overflows
Stops the TIM counter
Resets the TIM counter
Prescales the TIM counter clock
F
Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
n
.