MC68HC908AS60ACFN FREESCALE [Freescale Semiconductor, Inc], MC68HC908AS60ACFN Datasheet - Page 247

• Manufacturer Part Number: MC68HC908AS60ACFN
• Description: M68HC08 Microcontrollers
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

21.7.2 PIT Counter Registers
The two read-only PIT counter registers contain the high and low bytes of the value in the PIT counter.
Reading the high byte (PCNTH) latches the contents of the low byte (PCNTL) into a buffer. Subsequent
reads of PCNTH do not affect the latched PCNTL value until PCNTL is read. Reset clears the PIT counter
registers. Setting the PIT reset bit (PRST) also clears the PIT counter registers.
Freescale Semiconductor
Address: $004C
Address: $004D
If you read PCNTH during a break interrupt, be sure to unlatch PCNTL by
reading PCNTL before exiting the break interrupt. Otherwise, PCNTL
retains the value latched during the break.
Reset:
Reset:
Read:
Read:
Write:
Write:
MC68HC908AZ60A • MC68HC908AS60A • MC68HC908AS60E Data Sheet, Rev. 6
Bit 15
Bit 15
Bit 7
Bit 7
Figure 21-4. PIT Counter Registers (PCNTH–PCNTL)
0
0
PPS[2:0]
000
001
010
011
100
101
110
111
= Unimplemented
14
14
6
0
6
0
Table 21-2. Prescaler Selection
13
13
5
0
5
0
NOTE
12
12
4
0
4
0
Internal Bus Clock ÷ 16
Internal Bus Clock ÷ 32
Internal Bus Clock ÷ 64
Internal Bus Clock ÷ 64
Internal Bus Clock ÷ 2
Internal Bus Clock ÷ 4
Internal Bus Clock ÷ 8
Internal Bus Clock ÷1
PIT Clock Source
11
11
3
0
3
0
10
10
2
0
2
0
1
9
0
1
9
0
Bit 0
Bit 8
Bit 0
Bit 8
0
0
I/O Registers
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