C8051F800DK Silicon Laboratories Inc, C8051F800DK Datasheet - Page 129

• Manufacturer Part Number: C8051F800DK
• Description: KIT DEV C8051F800
• Manufacturer: Silicon Laboratories Inc
• Type: MCUr

Specifications of C8051F800DK

• Contents: Board, Cables, CD, Debugger, Power Supply
• Processor To Be Evaluated: C8051F800
• Data Bus Width: 16 bit
• Interface Type: USB
• Operating Supply Voltage: 7 V to 15 V
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• For Use With/related Products: C8051F8xx
• Lead Free Status / Rohs Status: Supplier Unconfirmed
• Other names: 336-1797

22. Oscillators and Clock Selection
C8051F80x-83x devices include a programmable internal high-frequency oscillator and an external oscilla-
tor drive circuit. The internal high-frequency oscillator can be enabled/disabled and calibrated using the
OSCICN and OSCICL registers, as shown in Figure 22.1. The system clock can be sourced by the exter-
nal oscillator circuit or the internal oscillator (default). The internal oscillator offers a selectable post-scaling
feature, which is initially set to divide the clock by 8.
22.1. System Clock Selection
The system clock source for the MCU can be selected using the CLKSEL register. The clock selected as
the system clock can be divided by 1, 2, 4, 8, 16, 32, 64, or 128. When switching between two clock divide
values, the transition may take up to 128 cycles of the undivided clock source. The CLKRDY flag can be
polled to determine when the new clock divide value has been applied. The clock divider must be set to
"divide by 1" when entering Suspend mode. The system clock source may also be switched on-the-fly. The
switchover takes effect after one clock period of the slower oscillator.
Option 4 – CMOS Mode
Option 1 – Crystal Mode
Option 3 – C Mode
Option 2 – RC Mode
XTAL2
VDD
XTAL2
XTAL2
10M
XTAL1
XTAL2
Figure 22.1. Oscillator Options
OSCICL
Circuit
Input
Programmable
Internal Clock
Generator
OSCXCN
Rev. 1.0
OSC
EN
OSCICN
Clock Divider
n
C8051F80x-83x
CLKSEL
Clock Divider
n
CLKRDY
SYSCLK
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