mc68hc908as60 Freescale Semiconductor, Inc, mc68hc908as60 Datasheet - Page 294

• Manufacturer Part Number: mc68hc908as60
• Description: Mc68hc908as60 Microcontroller
• Manufacturer: Freescale Semiconductor, Inc

Modulo Timer (TIM)
19.5 TIM Counter Prescaler
19.6 Low-Power Modes
19.6.1 Wait Mode
19.6.2 Stop Mode
Technical Data
The clock source can be one of the seven prescaler outputs. The
prescaler generates seven clock rates from the internal bus clock. The
prescaler select bits, PS2–PS0, in the status and control register select
the TIM clock source.
The value in the TIM counter modulo registers and the selected
prescaler output determines the frequency of the periodic interrupt. The
TIM overflow flag (TOF) is set when the TIM counter value rolls over to
$0000 after matching the value in the TIM counter modulo registers. The
TIM interrupt enable bit, TOIE, enables TIM overflow CPU interrupt
requests. TOF and TOIE are in the TIM status and control register.
The WAIT and STOP instructions put the MCU in low power-
consumption standby modes.
The TIM remains active after the execution of a WAIT instruction. In wait
mode the TIM registers are not accessible by the CPU. Any enabled
CPU interrupt request from the TIM can bring the MCU out of wait mode.
If TIM functions are not required during wait mode, reduce power
consumption by stopping the TIM before executing the WAIT instruction.
The TIM is inactive after the execution of a STOP instruction. The STOP
instruction does not affect register conditions or the state of the TIM
counter. TIM operation resumes when the MCU exits stop mode after an
external interrupt.
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Modulo Timer (TIM)
MC68HC908AS60 — Rev. 1.0