s908qc16vdse Freescale Semiconductor, Inc, s908qc16vdse Datasheet - Page 121

• Manufacturer Part Number: s908qc16vdse
• Description: M68hc08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

12.8.3 Periodic Wakeup Modulo Register
The PWU modulo register contains the modulo value for the counter. When the counter reaches the
modulo value, the PWU flag (PWUF) becomes set, and the counter resumes counting from $00 at the
next PWU clock. If PWUIE is set, a PWU interrupt is requested.The value in the PWUMOD register and
the selected prescaler output determine the frequency of the periodic interrupt. The frequency of the
periodic interrupt can be calculated by multiplying the prescaler period (see
the modulo register.
Freescale Semiconductor
Reset:
Read:
Write:
The PWUMOD register can only be written to when PWUON is clear.
MC68HC908QC16 • MC68HC908QC8 • MC68HC908QC4 Data Sheet, Rev. 4
Figure 12-4. Periodic Wakeup Modulo Register (PWUMOD)
Bit 7
Bit 7
PS3-PS0
0
0000
0001
0010
0011
0100
0101
0110
0111
1000
1001
1010
1011
1100
1101
1110
1111
Bit 6
6
0
PWU Counter Clock Source
Table 12-1. Prescaler Selection
(PWU Clock Divided by:)
Bit 5
5
0
16384
32768
1024
2048
4096
8192
256
512
128
16
64
32
1
8
2
4
NOTE
Bit 4
4
0
Bit 3
3
0
Nominal Period
Bit 2
2
0
(@ 32kHz)
31.25 µs
62.5 µs
128 ms
256 ms
512 ms
125 µs
250 µs
500 µs
16 ms
32 ms
64 ms
1 ms
2 ms
4 ms
8 ms
1 s
Bit 1
Table
1
0
12-1) by the value in
Bit 0
Bit 0
0
Registers
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