MC68HC08AZ60ACFU MOTOROLA [Motorola, Inc], MC68HC08AZ60ACFU Datasheet - Page 307

• Manufacturer Part Number: MC68HC08AZ60ACFU
• Description: Microcontrollers
• Manufacturer: MOTOROLA [Motorola, Inc]

19.5 PIT Counter Prescaler
MC68HC08AZ60A — Rev 0.0
MOTOROLA
PIT Counter Modulo Register High
PIT Counter Modulo Register Low
PIT Status and Control Register
Register Name
PIT Counter Register High
PIT Counter Register Low
(PMODH)
(PMODL)
(PCNTH)
(PCNTL)
(PSC)
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, PPS[2:0], in the status and control register select
the PIT clock source.
The value in the PIT counter modulo registers and the selected prescaler
output determines the frequency of the periodic interrupt. The PIT
overflow flag (POF) is set when the PIT counter value reaches the
Reset:
Reset:
Reset:
Reset:
Reset:
Read:
Write:
Read:
Write:
Read:
Write:
Read:
Write:
Read:
Write:
Figure 19-2. PIT I/O Register Summary
Bit 7
Bit 15
Bit 15
POF
Bit 7
Bit 7
Programmable Interrupt Timer (PIT)
0
0
0
0
1
1
Table 19-1. PIT I/O Register Address Summary
Register
Address
=Unimplemented
POIE
14
14
6
0
0
6
0
1
6
1
$004B
PSC
PSTOP
13
13
5
1
0
5
0
1
5
1
PCNTH
$004C
PRST
12
12
4
0
0
0
4
0
1
4
1
PCNTL
$004D
Programmable Interrupt Timer (PIT)
11
11
3
0
0
0
3
0
1
3
1
PMODH
$004E
PPS2
10
10
2
0
0
2
0
1
2
1
PIT Counter Prescaler
PMODL
Advance Information
$004F
PPS1
1
0
9
0
1
0
9
1
1
1
Bit 0
PPS0
Bit 8
Bit 0
Bit 8
Bit 0
0
0
0
1
1
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