
PIC18F6585/8585/6680/8680
DS30491C-page 178
2004 Microchip Technology Inc.
TABLE 16-2:
EXAMPLE PWM FREQUENCIES AND RESOLUTIONS AT 40 MHz
FIGURE 16-2:
SIMPLIFIED BLOCK DIAGRAM OF THE ENHANCED PWM MODULE
FIGURE 16-3:
PWM OUTPUT RELATIONSHIPS (ACTIVE-HIGH STATE)
PWM Frequency
2.44 kHz
9.77 kHz
39.06 kHz
156.25 kHz
312.50 kHz
416.67 kHz
Timer Prescaler (1, 4, 16)
16
41111
PR2 Value
FFh
3Fh
1Fh
17h
Maximum Resolution (bits)
10
8
7
6.58
CCPR1L
CCPR1H (Slave)
Comparator
TMR2
Comparator
PR2
(Note 1)
RQ
S
Duty Cycle Registers
CCP1CON<5:4>
Clear Timer,
set CCP1 pin and
latch D.C.
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.
2:
Alternate setting controlled by the ECCPMX bit (PIC18F8X8X devices only).
TRISC<2>
RC2/CCP1/P1A
TRISE<6>
RE6/AD14/P1B or RH7(2)
TRISE<5>
TRISG<4>
RG4/P1D
Output
Controller
P1M1<1:0>
2
CCP1M<3:0>
4
CCP1DEL
CCP1/P1A
P1B
P1C
P1D
RE5/AD13/P1C or RH6(2)
0
Period
00
10
01
11
SIGNAL
PR2 + 1
CCP1CON
<7:6>
P1A Modulated
P1B Modulated
P1A Active
P1B Inactive
P1C Inactive
P1D Modulated
P1A Inactive
P1B Modulated
P1C Active
P1D Inactive
Duty
Cycle
(Single Output)
(Half-Bridge)
(Full-Bridge,
Forward)
(Full-Bridge,
Reverse)
Delay(1)
Note 1: