s908gr32ag3vfa Freescale Semiconductor, Inc, s908gr32ag3vfa Datasheet - Page 223

• Manufacturer Part Number: s908gr32ag3vfa
• Description: M68hc08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

As an example, a 4.9152 MHz crystal, with the TMBCLKSEL set for divide-by-128 and the TBR2–TBR0
set to {011}, the divider is 16,384 and the interrupt rate calculates to:
16.6 Low-Power Modes
The WAIT and STOP instructions put the MCU in low power- consumption standby modes.
16.6.1 Wait Mode
The timebase module remains active after execution of the WAIT instruction. In wait mode the timebase
register is not accessible by the CPU.
If the timebase functions are not required during wait mode, reduce the power consumption by stopping
the timebase before executing the WAIT instruction.
16.6.2 Stop Mode
The timebase module may remain active after execution of the STOP instruction if the oscillator has been
enabled to operate during stop mode through the OSCENINSTOP bit in the configuration register. The
timebase module can be used in this mode to generate a periodic wakeup from stop mode.
If the oscillator has not been enabled to operate in stop mode, the timebase module will not be active
during stop mode. In stop mode, the timebase register is not accessible by the CPU.
If the timebase functions are not required during stop mode, reduce power consumption by disabling the
timebase module before executing the STOP instruction.
Freescale Semiconductor
4.9152 x 10
Do not change TBR2–TBR0 bits while the timebase is enabled (TBON = 1).
16,384
MC68HC908GR60A • MC68HC908GR48A • MC68HC908GR32A Data Sheet, Rev. 5
TBR2
6
0
0
0
0
1
1
1
1
= 3.33 ms
Table 16-1. Timebase Divider Selection
TBR1
0
0
1
1
0
0
1
1
TBR0
0
1
0
1
0
1
0
1
NOTE
32,768
8192
2048
128
64
32
16
0
8
TMBCLKSEL
Divider
4,194,304
1,048,576
262144
16,384
8192
4096
2048
1024
1
Low-Power Modes
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