MC68HC912BD32 Datasheet, PDF (124/292 Pages) Freescale Semiconductor, Inc – Advance Information

Freescale Semiconductor, Inc.
Pulse Width Modulator
PWCNTx — PWM Channel Counters
Bit 7
6
5
4
3
2
1
Bit 0
PWCNT0 Bit 7
6
5
4
3
2
1
Bit 0
$0048
PWCNT1 Bit 7
6
5
4
3
2
1
Bit 0
$0049
PWCNT2 Bit 7
6
5
4
3
2
1
Bit 0
$004A
PWCNT3 Bit 7
6
5
4
3
2
1
Bit 0
$004B
RESET
0
0
0
0
0
0
0
0
Read and write anytime. A write will cause the PWM counter to reset
to $00.
In Special mode, if DISCR = 1, a write does not reset the PWM
counter.
Each channel has its own counter. Each counter may be read any
time without affecting the count or the operation of the corresponding
PWM channel. Writes to a counter cause the counter to be reset to
$00 and force an immediate load of both duty and period registers
with new values. In concatenated mode, writes to the 16-bit counter
by using 16 bit access, or writes to the high order byte of the counter,
will cause reset of the 16-bit counters.Writes to the lower byte of the
counter have no effect. Reads of the 16-bit counter should be made
only by 16 bit access to maintain data coherency.
PWPERx — PWM Channel Period Registers
Bit 7
6
5
4
3
2
1
Bit 0
PWPER0 Bit 7
6
5
4
3
2
1
Bit 0
$004C
PWPER1 Bit 7
6
5
4
3
2
1
Bit 0
$004D
PWPER2 Bit 7
6
5
4
3
2
1
Bit 0
$004E
PWPER3 Bit 7
6
5
4
3
2
1
Bit 0
$004F
RESET
1
1
1
1
1
1
1
1
Read and write anytime.
There is a dedicated period register for each channel. The value in the
period register determines the period of the associated PWM
channel. If written while the channel is enabled, the new value will not
take effect until the existing period terminates, forcing the counter to
reset. The new period is then latched and is used until a new period
MC68HC912BD32 Rev 1.0
Pulse Width Modulator
For More Information On This Product,
Go to: www.freescale.com
12-pwm