C8051F320-TB Silicon Laboratories Inc, C8051F320-TB Datasheet - Page 116

• Manufacturer Part Number: C8051F320-TB
• Description: BOARD PROTOTYPING W/C8051F320
• Manufacturer: Silicon Laboratories Inc
• Type: MCUr

Specifications of C8051F320-TB

• Contents: Board
• Processor To Be Evaluated: C8051F320/F321
• Interface Type: USB
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• For Use With/related Products: C8051F320
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

C8051F320/1
13. Oscillators
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 oscillator, external oscillator, or 4x Clock Multiplier. Oscillator electrical specifi-
cations are given in Table 13.3 on page 125.
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
internal oscillator period, and OSCICL is a change to the value held in register OSCICL.
116
VDD
Option 2
XTAL2
Option 1
Option 4
10M
XTAL2
Option 3
XTAL2
XTAL1
XTAL2
BASE
is the frequency of the internal oscillator following a reset, T is the change in
Figure 13.1. Oscillator Diagram
OSCICL
Circuit
Input
Programmable
Internal Clock
Generator
OSCXCN
OSC
EN
Rev. 1.4
EXOSC / 2
OSCICN
IOSC
EXOSC
EXOSC
IOSC
CLKMUL
n
Clock Multiplier
x 2
x 2
EXOSC / 2
EXOSC / 3
EXOSC / 4
IOSC / 2
EXOSC
CLKSEL
SYSCLK
USBCLK