
2007 Microchip Technology Inc.
Preliminary
DS70165E-page 173
dsPIC33F
TABLE 14-1:
EXAMPLE PWM FREQUENCIES AND RESOLUTIONS AT 4 MIPS (FCY = 4 MHz)
TABLE 14-2:
EXAMPLE PWM FREQUENCIES AND RESOLUTIONS AT 16 MIPS (FCY = 16 MHz)
TABLE 14-3:
EXAMPLE PWM FREQUENCIES AND RESOLUTIONS AT 40 MIPS (FCY = 40 MHz)
FIGURE 14-1:
OUTPUT COMPARE MODULE BLOCK DIAGRAM
PWM Frequency
7.6 Hz
61 Hz
122 Hz
977 Hz
3.9 kHz
31.3 kHz
125 kHz
Timer Prescaler Ratio
8
1
111
11
Period Register Value
FFFFh
7FFFh
0FFFh
03FFh
007Fh
001Fh
Resolution (bits)
16
15
12
10
7
5
PWM Frequency
30.5 Hz
244 Hz
488 Hz
3.9 kHz
15.6 kHz
125 kHz
500 kHz
Timer Prescaler Ratio
8
1
111
11
Period Register Value
FFFFh
7FFFh
0FFFh
03FFh
007Fh
001Fh
Resolution (bits)
16
15
12
10
7
5
PWM Frequency
76 Hz
610 Hz
1.22 Hz
9.77 kHz
39 kHz
313 kHz
1.25 MHz
Timer Prescaler Ratio
8
1
111
11
Period Register Value
FFFFh
7FFFh
0FFFh
03FFh
007Fh
001Fh
Resolution (bits)
16
15
12
10
7
5
Note:
Only OC1 and OC2 can trigger a DMA data transfer.
OCxR(1)
Comparator
Output
Logic
OCM2:OCM0
Output Enable
OCx(1)
Set Flag bit
OCxIF(1)
OCxRS(1)
Mode Select
3
Note 1:Where ‘x’ is shown, reference is made to the registers associated with the respective output compare channels 1
through 8.
2: OCFA pin controls OC1-OC4 channels. OCFB pin controls OC5-OC8 channels.
3: Each output compare channel can use one of two selectable time bases. Refer to the device data sheet for the
time bases associated with the module.
OCTSEL
0
1
16
OCFA or OCFB(2)
TMR register inputs
from time bases(3)
Period match signals
from time bases(3)
0
1
Q
S
R