Table of Contents
Advertisement
The clock generation and distribution circuits provide uniform clock signals for the Execution
Unit, the Bus Interface Unit and all integrated peripherals. The 80C186 Modular Core Family
processors have additional logic that controls the clock signals to provide power management
functions.
5.1
CLOCK GENERATION
The clock generation circuit (Figure 5-1) includes a crystal oscillator, a divide-by-two counter
and power-save and reset circuitry. See "Power-Save Mode" on page 5-19 for a discussion of
Power-Save mode as a power management option.
CLKIN
OSCOUT
RESIN
5.1.1
Crystal Oscillator
The internal oscillator is a parallel resonant Pierce oscillator, a specific form of the common
phase shift oscillator.
CLOCK GENERATION AND POWER
Schmitt Trigger
"Squares-up" CLKIN
÷ 2
Clock
Clock
Divider
Reset Circuitry
Figure 5-1. Clock Generator
CHAPTER 5
MANAGEMENT
Power Down
Idle
Power Save
1
Phase
Drivers
2
To CLKOUT
Internal Reset
Internal
Phase
Clocks
A1118-0A
5-1
Advertisement
Table of Contents
