mc68hc05pv8 Freescale Semiconductor, Inc, mc68hc05pv8 Datasheet - Page 151

• Manufacturer Part Number: mc68hc05pv8
• Description: Hcmos Microcontroller Unit
• Manufacturer: Freescale Semiconductor, Inc

11.4.2 PWM Data Register
MC68HC(8)05PV8/A — Rev. 1.9
PRA3, PRA2, PRA1, PRA0 – PWM Clock Rate Bits
The PWM system has an 8-bit data register that holds the duty cycle for
the PWM output. This register can be changed at any time. When the
PWMDAT register is updated, the programmed value, as well as the
POL bit, take effect in the following conversion cycle. Note that if the
contents of PWMDAT are higher than the contents of PWMPR the
output will be permanently switched to the passive state (i.e. the same
result as PWMDAT = $00).
$002E
Reset:
Read:
Write:
PRA3:PRA0
These bits select the input clock rate f
Table
The PWM clock rate bits are not latched until the end of conversion.
They affect the PWM output immediately. For proper operation these
control bits must not be changed during conversion.
Freescale Semiconductor, Inc.
For More Information On This Product,
0000
0001
0010
0100
0101
0011
0110
0111
Bit 7
bit 7
11-1.
0
Figure 11-5 PWM Data Register (PWMDAT)
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Pulse Width Modulator
bit 6
6
0
Table 11-1 PWM Clock Rate
f
f
osc
f
f
f
f
f
f
osc
osc
osc
osc
osc
osc
PWM
f
bit 5
osc
/1.5
5
0
/12
/2
/3
/4
/6
/8
bit 4
4
0
PRA3:PRA0
PWM
bit 3
3
0
1000
1001
1010
1011
1100
1101
1110
1111
. For exact values see
bit 2
2
0
Pulse Width Modulator
bit 1
1
0
Technical Data
f
f
f
f
f
f
f
f
osc
osc
osc
osc
osc
osc
osc
osc
f
PWM
/128
/192
/16
/24
/32
/48
/64
/96
Registers
Bit 0
bit 0
0