PIC32MX440F256H-80I Datasheet, PDF (571/646 Pages) Microchip Technology – 64/100-Pin General Purpose and USB 32-Bit Flash Microcontrollers

PIC32MX3XX/4XX
REGISTER 27-2: DEVCFG1: DEVICE CONFIGURATION WORD 1 (CONTINUED)
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 mode (EC) 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 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 bit
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)⁽¹⁾
011 = Primary Oscillator with PLL module (XT+PLL, HS+PLL, EC+PLL)
100 = Secondary Oscillator (SOSC)
101 = Low-Power RC Oscillator (LPRC)
110 = FRCDIV16 Fast RC Oscillator with fixed divide-by-16 postscaler
111 = Fast RC Oscillator with divide-by-N (FRCDIV)
Note 1: Do not disable POSC (POSCMD = 00) when using this oscillator source.
© 2008 Microchip Technology Inc.
Preliminary
DS61143E-page 569