
PIC32MX1XX/2XX
DS61168D-page 102
Preliminary
2011-2012 Microchip Technology Inc.
bit 7-4
Unimplemented: Read as ‘0’
bit 3-0
ROSEL<3:0>: Reference Clock Source Select bits(1)
1111 = Reserved; do not use
1001 = Reserved; do not use
1000 = REFCLKI
0111 = System PLL output
0110 = USB PLL output
0101 =SOSC
0100 =LPRC
0011 =FRC
0010 =POSC
0001 = PBCLK
0000 = SYSCLK
REGISTER 8-3:
REFOCON: REFERENCE OSCILLATOR CONTROL REGISTER
Note 1: The ROSEL and RODIV bits should not be written while the ACTIVE bit is ‘1’, as undefined behavior may
result.
2: This bit is ignored when the ROSEL<3:0> bits = 0000 or 0001.
3: While the ON bit is set to ‘1’, writes to these bits do not take effect until the DIVSWEN bit is also set to’1’.