C8051F321 Silicon Laboratories Inc, C8051F321 Datasheet - Page 122

• Manufacturer Part Number: C8051F321
• Description: IC 8051 MCU 16K FLASH 28MLP
• Manufacturer: Silicon Laboratories Inc
• Series: C8051F32xr

Specifications of C8051F321

• Core Processor: 8051
• Core Size: 8-Bit
• Speed: 25MHz
• Connectivity: SMBus (2-Wire/I²C), SPI, UART/USART, USB
• Peripherals: Brown-out Detect/Reset, POR, PWM, Temp Sensor, WDT
• Number Of I /o: 21
• Program Memory Size: 16KB (16K x 8)
• Program Memory Type: FLASH
• Ram Size: 2.25K x 8
• Voltage - Supply (vcc/vdd): 2.7 V ~ 3.6 V
• Data Converters: A/D 13x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 28-VQFN Exposed Pad, 28-HVQFN, 28-SQFN, 28-DHVQFN
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -

C8051F320/1
122
Bit7:
Bits6-4:
Bit3:
Bits2-0:
CRYSTAL MODE (Circuit from Figure 13.1, Option 1; XOSCMD = 11x)
RC MODE (Circuit from Figure 13.1, Option 2; XOSCMD = 10x)
C MODE (Circuit from Figure 13.1, Option 3; XOSCMD = 10x)
XTLVLD XOSCMD2 XOSCMD1 XOSCMD0
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.
XOSCMD2-0: External Oscillator Mode Bits.
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 = 0, Write = don't care.
XFCN2-0: External Oscillator Frequency Control Bits.
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 = Pull-up resistor value in kΩ
Choose K Factor (KF) for the oscillation frequency desired:
f = KF / (C * VDD), where
f = frequency of clock in MHz
C = capacitor value the XTAL2 pin in pF
VDD = Power Supply on MCU in volts
XFCN
000
001
010
011
100
101
110
111
R/W
Bit6
Figure 13.4. OSCXCN: External Oscillator Control Register
3
) / (R * C), where
Crystal (XOSCMD = 11x)
R/W
Bit5
590kHz < f ≤ 1.5MHz
225kHz < f ≤ 590kHz
10MHz < f ≤ 30MHz
1.5MHz < f ≤ 4MHz
84kHz < f ≤ 225kHz
4MHz < f ≤ 10MHz
32kHz < f ≤ 84kHz
f ≤ 32kHz
R/W
Bit4
Rev. 1.1
Bit3
R
-
RC (XOSCMD = 10x)
1.6MHz < f ≤ 3.2MHz
800kHz < f ≤ 1.6MHz
200kHz < f ≤ 400kHz
400kHz < f ≤ 800kHz
100kHz < f ≤ 200kHz
50kHz < f ≤ 100kHz
25kHz < f ≤ 50kHz
f ≤ 25kHz
XFCN2
R/W
Bit2
XFCN1
R/W
Bit1
C (XOSCMD = 10x)
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
XFCN0
R/W
Bit0
SFR Address:
00000000
Reset Value
0xB1