PIC16F631/677/685/687/689/690
11.4.7
PULSE STEERING MODE
In Single Output mode, pulse steering allows any of the
PWM pins to be the modulated signal. Additionally, the
same PWM signal can be simultaneously available on
multiple pins.
Note:
The associated TRIS bits must be set to
output (‘0’) to enable the pin output driver
in order to see the PWM signal on the pin.
While the PWM Steering mode is active, CCP1M<1:0>
bits of the CCP1CON register select the PWM output
polarity for the P1<D:A> pins.
Once the Single Output mode is selected
(CCP1M<3:2> = 11 and P1M<1:0> = 00 of the
CCP1CON register), the user firmware can bring out
the same PWM signal to one, two, three or four output
pins by setting the appropriate STR<D:A> bits of the
PSTRCON register, as shown in Figure 11-18.
The PWM auto-shutdown operation also applies to
PWM Steering mode as described in Section 11.4.4
“Enhanced PWM Auto-shutdown mode”. An
auto-shutdown event will only affect pins that have
PWM outputs enabled.
REGISTER 11-4: PSTRCON: PULSE STEERING CONTROL REGISTER(1)
U-0
—
U-0
—
U-0
—
R/W-0
R/W-0
STRD
R/W-0
STRC
R/W-0
STRB
R/W-1
STRA
STRSYNC
bit 7
bit 0
Legend:
R = Readable bit
-n = Value at POR
W = Writable bit
‘1’ = Bit is set
U = Unimplemented bit, read as ‘0’
‘0’ = Bit is cleared x = Bit is unknown
bit 7-5
bit 4
Unimplemented: Read as ‘0’
STRSYNC: Steering Sync bit
1= Output steering update occurs on next PWM period
0= Output steering update occurs at the beginning of the instruction cycle boundary
bit 3
bit 2
bit 1
bit 0
STRD: Steering Enable bit D
1= P1D pin has the PWM waveform with polarity control from CCP1M<1:0>
0= P1D pin is assigned to port pin
STRC: Steering Enable bit C
1= P1C pin has the PWM waveform with polarity control from CCP1M<1:0>
0= P1C pin is assigned to port pin
STRB: Steering Enable bit B
1= P1B pin has the PWM waveform with polarity control from CCP1M<1:0>
0 = P1B pin is assigned to port pin
STRA: Steering Enable bit A
1= P1A pin has the PWM waveform with polarity control from CCP1M<1:0>
0= P1A pin is assigned to port pin
Note 1: The PWM Steering mode is available only when the CCP1CON register bits CCP1M<3:2> = 11and
P1M<1:0> = 00.
© 2007 Microchip Technology Inc.
DS41262D-page 145
MICROCHIP [ MICROCHIP ]
