Datasheet

 2010 Microchip Technology Inc. DS41302D-page 97
PIC12F609/615/617/12HV609/615
11.4 PWM (Enhanced Mode)
The Enhanced PWM Mode can generate a PWM signal
on up to four different output pins with up to 10-bits of
resolution. It can do this through four different PWM
output modes:
• Single PWM
• Half-Bridge PWM
To select an Enhanced PWM mode, the P1M bits of the
CCP1CON register must be set appropriately.
The PWM outputs are multiplexed with I/O pins and are
designated P1A and P1B. The polarity of the PWM pins
is configurable and is selected by setting the CCP1M
bits in the CCP1CON register appropriately.
Table 11-6 shows the pin assignments for each
Enhanced PWM mode.
Figure 11-5 shows an example of a simplified block
diagram of the Enhanced PWM module.
FIGURE 11-5: EXAMPLE SIMPLIFIED BLOCK DIAGRAM OF THE ENHANCED PWM MODE
TABLE 11-6: EXAMPLE PIN ASSIGNMENTS FOR VARIOUS PWM ENHANCED MODES
Note: To prevent the generation of an
incomplete waveform when the PWM is
first enabled, the ECCP module waits until
the start of a new PWM period before
generating a PWM signal.
CCPR1L
CCPR1H (Slave)
Comparator
TMR2
Comparator
PR2
(1)
RQ
S
Duty Cycle Registers
CCP1<1:0>
Clear Timer2,
toggle PWM pin and
latch duty cycle
* Alternate pin function.
Note 1: The 8-bit timer TMR2 register is concatenated with the 2-bit internal Q clock, or 2 bits of the prescaler to create the 10-bit time base.
TRISIO2
CCP1/P1A
Output
Controller
P1M<1:0>
2
CCP1M<3:0>
4
PWM1CON
CCP1/P1A
P1B
0
1
TRISIO5
CCP1/P1A*
P1ASEL
(APFCON<0>)
TRISIO0
P1B
0
1
TRISIO4
P1B*
P1BSEL
(APFCON<1>)
Note 1: The TRIS register value for each PWM output must be configured appropriately.
2: Clearing the CCP1CON register will relinquish ECCP control of all PWM output pins.
3: Any pin not used by an Enhanced PWM mode is available for alternate pin functions.
ECCP Mode P1M<1:0> CCP1/P1A P1B
Single 00 Yes
(1)
Yes
(1)
Half-Bridge 10 Yes Yes