PIC32MX440F256H-80I Datasheet, PDF (562/646 Pages) Microchip Technology – 64/100-Pin General Purpose and USB 32-Bit Flash Microcontrollers

PIC32MX3XX/4XX
REGISTER 26-3: DEVCFG1: DEVICE CONFIGURATION WORD 1
bit 15-14
FCKSM<1:0>: Clock Switching and Monitor Selection Configuration bits
1x = Clock switching is disabled, Fail-Safe Clock Monitor is disabled
01 = Clock switching is enabled, Fail-Safe Clock Monitor is disabled
00 = Clock switching is enabled, Fail-Safe Clock Monitor is enabled
bit 13-12
FPBDIV<1:0>: Peripheral Bus Clock Divisor Default Value bits
11 = PBCLK is SYSCLK divided by 8
10 = PBCLK is SYSCLK divided by 4
01 = PBCLK is SYSCLK divided by 2
00 = PBCLK is SYSCLK divided by 1
bit 11
Reserved: Write ‘1’
bit 10
OSCIOFNC: CLKO Enable Configuration bit
1 = CLKO output signal active on the OSCO pin; primary oscillator must be disabled or configured for
the External Clock (EC) mode for the CLKO to be active (POSCMD<1:0> = 11 or 00)
0 = CLKO output disabled
bit 9-8
POSCMD<1:0>: Primary Oscillator Configuration bits
11 = Primary oscillator is disabled
10 = HS Oscillator mode selected
01 = XT Oscillator mode selected
00 = External Clock mode selected
bit 7
IESO: Internal External Switchover bit
1 = Internal External Switchover mode enabled (Two-Speed Start-Up enabled)
0 = Internal External Switchover mode disabled (Two-Speed Start-Up disabled)
bit 6
Reserved: Write ‘1’
bit 5
FSOSCEN: Secondary Oscillator Enable bits
1 = Enable secondary oscillator
0 = Disable secondary oscillator
bit 4-3
Reserved: Write ‘1’
bit 2-0
FNOSC<2:0>: Oscillator Selection bits
000 = Fast RC Oscillator (FRC)
001 = Fast RC Oscillator with divide-by-N with PLL module (FRCDIV + PLL)
010 = Primary Oscillator (XT, HS, EC)⁽²⁾
011 = Primary Oscillator with PLL module (XT + PLL, HS + PLL, EC + PLL)⁽²⁾
100 = Secondary Oscillator
101 = Low-Power RC Oscillator (LPRC)
110 = FRCDIVIG Fast RC Oscillator with fixed divide-by-16 postscaler
111 = Fast RC Oscillator with divide-by-N (FRCDIV)
Note 1: All combinations not listed result in operation as if the selection was 10100.
2: Do not disable POSC (POSCMD = 00) when using this oscillator source.
DS61143E-page 560
Preliminary
© 2008 Microchip Technology Inc.