c8051t602 Silicon Laboratories, c8051t602 Datasheet - Page 91

• Manufacturer Part Number: c8051t602
• Description: Mixed Signal Otp Eprom Mcu Family
• Manufacturer: Silicon Laboratories

12. Oscillators
All C8051T600/1/2/3/4/5 devices include a calibrated, precision internal oscillator and an external clock
input circuit. The external clock input circuitry can be configured to operate from a CMOS clock, an exter-
nal capacitor, or an external RC circuit. The internal oscillator can be enabled/disabled and adjusted using
the OSCICN and OSCICL registers, as shown in Figure 12.1. The system clock can be sourced by the
external clock input circuit, the internal oscillator, or a scaled version of the internal oscillator. The internal
oscillator's electrical specifications are given in Table 12.1 on page 92.
12.1. Calibrated Internal Oscillator
All C8051T600/1/2/3/4/5 devices include a calibrated internal oscillator that defaults as the system clock
after a system reset. The oscillator is factory calibrated to obtain a 24.5 MHz frequency at room tempera-
ture, using the OSCICL register.
The controller’s core clock (SYSCLK) may be derived from the 24.5 MHz internal oscillator divided by 1, 2,
4, or 8, as defined by the IFCN bits in register OSCICN. The divide value defaults to 8 following a reset,
producing a 3.0625 MHz system clock.
Option 2
EXTCLK
Option 1
EXTCLK
VDD
Option 3
EXTCLK
EXTCLK
Figure 12.1. Oscillator Diagram
OSCICL
Circuit
Input
Internal Clock
Rev. 0.5
Generator
OSCXCN
EN
OSC
OSCICN
C8051T600/1/2/3/4/5
n
SYSCLK
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