Intel 87C196CB, 8XC196NT user manual Chapter Special Operating Modes, 1. Clock Circuitry

Models: 8XC196NT 87C196CB

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CHAPTER 8

CHAPTER 8

SPECIAL OPERATING MODES

8.1CLOCK CIRCUITRY

The 87C196CB’s idle, powerdown, and ONCE modes are the same as those of the 8XC196NT. The only difference is in the way that the power saving modes disable the clock circuitry (Figure 8-1).

 

Disable

 

 

 

 

 

PLL

 

 

 

 

 

(Powerdown)

 

 

 

 

FXTAL1

 

 

 

Phase

Filter

XTAL1

 

 

 

Comparator

 

 

 

 

 

 

XTAL1

 

 

Phase-

 

 

 

 

locked

 

XTAL2

F

 

 

 

XTAL1

 

 

Oscillator

 

Disable

Disable Clock Input

 

 

4F

Phase-locked Loop

Oscillator

(Powerdown)

 

 

Clock Multiplier

 

 

 

 

(Powerdown)

 

 

 

 

 

 

 

 

 

 

f

Divide-by-two

 

 

 

 

 

Circuit

 

 

 

PLLEN

 

f

Disable Clocks

 

 

2

(Powerdown)

 

 

 

 

 

 

 

 

Peripheral Clocks (PH1, PH2)

 

 

Clock

 

CLKOUT

 

 

 

Generators

 

 

 

 

 

 

 

 

 

 

 

CPU Clocks (PH1, PH2)

 

 

 

Disable Clocks

 

 

 

(Idle, Powerdown)

 

 

 

 

 

 

A3168-01

Figure 8-1. Clock Circuitry

8-1

Page 106
Image 106
Intel 87C196CB, 8XC196NT user manual Chapter Special Operating Modes, 1. Clock Circuitry