C8051T600SDB Silicon Laboratories Inc, C8051T600SDB Datasheet - Page 100

• Manufacturer Part Number: C8051T600SDB
• Description: BOARD SOCKET DAUGHTER SOIC
• Manufacturer: Silicon Laboratories Inc

Specifications of C8051T600SDB

• Module/board Type: Socket Module - SOIC
• Data Bus Width: 8 bit
• Operating Supply Voltage: + 1.8 V to + 3.6 V
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• For Use With/related Products: C8051T600DK
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 336-1405

C8051T600/1/2/3/4/5/6
21. Oscillators and Clock Selection
C8051T600/1/2/3/4/5/6 devices include a programmable internal high-frequency oscillator and an external
oscillator drive circuit. The internal high-frequency oscillator can be enabled/disabled and calibrated using
the OSCICN and OSCICL registers, as shown in Figure 21.1. The system clock can be sourced by the
external 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.
OSCICL
OSCICN
RC Mode
VDD
EXTCLK
EN
Programmable
n
Internal Clock
Generator
SYSCLK
C Mode
EXTCLK
Input
EXTCLK
OSC
Circuit
CMOS Mode
EXTCLK
OSCXCN
Figure 21.1. Oscillator Options
21.1. System Clock Selection
The CLKSL bit in register OSCICN selects which oscillator source is used as the system clock. CLKSL
must be set to 1 for the system clock to run from the external oscillator; however the external oscillator may
still clock certain peripherals (timers, PCA) when the internal oscillator is selected as the system clock. The
system clock may be switched on-the-fly between the internal oscillator and external oscillator, as long as
the selected clock source is enabled and running.
The internal high-frequency oscillator requires little start-up time and may be selected as the system clock
immediately following the register write, which enables the oscillator. The external RC and C modes also
typically require no startup time.
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Rev. 1.2