Si1000/1/2/3/4/5
SFR Definition 19.4. OSCXCN: External Oscillator Control
Bit
7
6
5
4
3
2
1
0
XCLKVLD
XOSCMD[2:0]
Reserved
XFCN[2:0]
Name
Type
Reset
R
0
R
0
R/W
0
R/W
0
R/W
0
R/W
0
R/W
0
R/W
0
SFR Page = 0x0; SFR Address = 0xB1
Bit
Name
XCLKVLD External Oscillator Valid Flag.
Function
7
Provides External Oscillator status and is valid at all times for all modes of operation
except External CMOS Clock Mode and External CMOS Clock Mode with divide by
2. In these modes, XCLKVLD always returns 0.
0: External Oscillator is unused or not yet stable.
1: External Oscillator is running and stable.
6:4
XOSCMD External Oscillator Mode Bits.
Configures the external oscillator circuit to the selected mode.
00x: External Oscillator circuit disabled.
010: External CMOS Clock Mode.
011: External CMOS Clock Mode with divide by 2 stage.
100: RC Oscillator Mode.
101: Capacitor Oscillator Mode.
110: Crystal Oscillator Mode.
111: Crystal Oscillator Mode with divide by 2 stage.
3
Reserved Read = 0b. Must Write 0b.
2:0
XFCN
External Oscillator Frequency Control Bits.
Controls the external oscillator bias current.
000-111: See Table 19.1 on page 184 (Crystal Mode) or Table 19.2 on page 185 (RC
or C Mode) for recommended settings.
Rev. 1.0
189