C8051F320 Silicon Laboratories Inc, C8051F320 Datasheet - Page 117

• Manufacturer Part Number: C8051F320
• Description: IC 8051 MCU 16K FLASH 32LQFP
• Manufacturer: Silicon Laboratories Inc
• Series: C8051F32xr

Specifications of C8051F320

• 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: 25
• 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 17x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 32-LQFP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Eeprom Size: -

13.
C8051F320/1 devices include a programmable internal oscillator, an external oscillator drive circuit, and a 4x Clock
Multiplier. The internal oscillator can be enabled/disabled and calibrated using the OSCICN and OSCICL registers,
as shown in Figure 13.1. The system clock (SYSCLK) can be derived from the internal oscillator, external oscillator
circuit, or the 4x Clock Multiplier divided by 2. The USB clock (USBCLK) can be derived from the internal oscilla-
tor, external oscillator, or 4x Clock Multiplier. Oscillator electrical specifications are given in Table 13.3 on page 126.
13.1. Programmable Internal Oscillator
All C8051F320/1 devices include a programmable internal oscillator that defaults as the system clock after a system
reset. The internal oscillator period can be programmed via the OSCICL register as defined by Equation 13.1, where
f
∆OSCICL is a change to the value held in register OSCICL.
BASE
VDD
Option 2
is the frequency of the internal oscillator following a reset, ∆T is the change in internal oscillator period, and
XTAL2
Option 1
OSCILLATORS
Equation 13.1. Typical Change in Internal Oscillator Period with OSCICL
Option 4
10MΩ
XTAL2
Option 3
XTAL2
XTAL1
XTAL2
OSCICL
∆T 0.0025
Figure 13.1. Oscillator Diagram
Circuit
Input
Programmable
Internal Clock
Generator
≅
OSCXCN
OSC
EN
×
EXOSC / 2
OSCICN
IOSC
EXOSC
------------ -
f
BASE
EXOSC
1
Rev. 1.1
IOSC
CLKMUL
×
∆OSCICL
n
Clock Multiplier
x 2
x 2
EXOSC / 2
EXOSC / 3
EXOSC / 4
IOSC / 2
EXOSC
C8051F320/1
CLKSEL
SYSCLK
USBCLK
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