4.7.1 CONFIG1

Oscillators
Name: CONFIG1
Offset: 0x300000

Configuration Word 1

Bit 15141312111098 
   FCMEN CSWEN  CLKOUTEN 
Access R/WR/WR/W 
Reset 111 
Bit 76543210 
  RSTOSC[2:0] FEXTOSC[2:0] 
Access R/WR/WR/WR/WR/WR/W 
Reset 111111 

Bit 13 – FCMEN Fail-Safe Clock Monitor Enable bit

ValueDescription
1 Fail-Safe Clock Monitor enabled
0 Fail-Safe Clock Monitor disabled

Bit 11 – CSWEN Clock Switch Enable bit

ValueDescription
1 Writing to NOSC and NDIV is allowed
0 The NOSC and NDIV bits cannot be changed by user software

Bit 8 – CLKOUTEN Clock Out Enable bit

If FEXTOSC = HS, XT, LP, then this bit is ignored.

Otherwise:

ValueDescription
1 CLKOUT function is disabled; I/O function on OSC2
0 CLKOUT function is enabled; FOSC/4 clock appears at OSC2

Bits 6:4 – RSTOSC[2:0] Power-up Default Value for COSC bits

This value is the Reset default value for COSC and selects the oscillator first used by user software. Refer to COSC operation.

ValueDescription
111 EXTOSC operating per FEXTOSC bits (device manufacturing default)
110 HFINTOSC with HFFRQ = 4 MHz and CDIV = 4:1
101 LFINTOSC
100 SOSC
011 Reserved
010 EXTOSC with 4x PLL, with EXTOSC operating per FEXTOSC bits
001 Reserved
000 HFINTOSC with HFFRQ = 64 MHz and CDIV = 1:1. Resets COSC/NOSC to b'110'.

Bits 2:0 – FEXTOSC[2:0] FEXTOSC External Oscillator Mode Selection bits

ValueDescription
111 ECH (external clock) above 16MHz
110 ECM (external clock) for 500 kHz to 16MHz
101 ECL (external clock) below 500 kHz
100 Oscillator not enabled
011 Reserved (do not use)
010 HS (crystal oscillator) above 4 MHz
001 XT (crystal oscillator) above 500 kHz, below 4 MHz
000 LP (crystal oscillator) optimized for 32.768 kHz