c8051f410 Silicon Laboratories, c8051f410 Datasheet - Page 171

• Manufacturer Part Number: c8051f410
• Description: 2.0 V, 32/16 Kb Flash, Smartclock, 12-bit Adc
• Manufacturer: Silicon Laboratories

Bit7:
Bits6–4: XOSCMD2–0: External Oscillator Mode Bits.
Bit3:
Bits2–0: XFCN2–0: External Oscillator Frequency Control Bits.
Crystal Mode (Circuit from Figure 19.1, Option 1; XOSCMD = 11x)
RC Mode (Circuit from Figure 19.1, Option 2; XOSCMD = 10x)
C Mode (Circuit from Figure 19.1, Option 3; XOSCMD = 10x)
XTLVLD XOSCMD2 XOSCMD1 XOSCMD0 Reserved
Bit7
R
XTLVLD: Crystal Oscillator Valid Flag. (Read only when XOSCMD = 11x.)
0: Crystal Oscillator is unused or not yet stable.
1: Crystal Oscillator is running and stable.
00x: External Oscillator circuit off.
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.
RESERVED. Read = 0b; Must write 0b.
000-111: See table below:
Choose XFCN value to match crystal or resonator frequency.
Choose XFCN value to match frequency range:
f = 1.23(10
f = frequency of clock in MHz
C = capacitor value in pF
R = Pullup resistor value in k Ω
Choose K Factor (KF) for the oscillation frequency desired:
f = KF / (C x V
f = frequency of clock in MHz
C = capacitor value the XTAL2 pin in pF
V
DD
XFCN
SFR Definition 19.3. OSCXCN: External Oscillator Control
R/W
000
001
010
011
100
101
110
Bit6
111
= Power Supply on MCU in volts
3
) / (R x C) , where
Crystal (XOSCMD = 11x)
DD
415 kHz < f ≤ 1.1 MHz
1.1 MHz < f ≤ 3.1 MHz
3.1 MHz < f ≤ 8.2 MHz
155 kHz < f ≤ 415 kHz
8.2 MHz < f ≤ 25 MHz
R/W
Bit5
58 kHz < f ≤ 155 kHz
20 kHz < f ≤ 58 kHz
) , where
f ≤ 20 kHz
R/W
Bit4
Rev. 1.0
R/W
Bit3
800 kHz < f ≤ 1.6 MHz
1.6 MHz < f ≤ 3.2 MHz
100 kHz < f ≤ 200 kHz
200 kHz < f ≤ 400 kHz
400 kHz < f ≤ 800 kHz
RC (XOSCMD = 10x)
50 kHz < f ≤ 100 kHz
25 kHz < f ≤ 50 kHz
XFCN2
f ≤ 25 kHz
R/W
Bit2
C8051F410/1/2/3
XFCN1
R/W
Bit1
SFR Address:
C (XOSCMD = 10x)
XFCN0
K Factor = 1590
K Factor = 0.87
K Factor = 180
K Factor = 664
K Factor = 2.6
K Factor = 7.7
K Factor = 22
K Factor = 65
R/W
Bit0
0xB1
00000000
Reset Value
171