12

* This specification are subject to be changed without notice.

7.20.1999

EM73201

4-BIT MICRO-CONTROLLER FOR GENERAL PURPOSE PRODUCT

Preliminary

XIN/CLK

XOUT

Crystal connection

XIN/CLK

XOUT

RC connection

fc

Prescaler

Binary counter

1 2 3

4

567 8910 11 12 13

22

21

20

19

18

17

16

15

14

CLOCK AND TIMING GENERATOR FUNCTION

The frequency of fc is the oscillation frequency for XIN, XOUT by crystal ( resonator) or for CLK by RC

osc.

When CPU sleeps, the XOUT pin will be in "high" state .

When user chooses RC osc, XOUT pin is no used .

The instruction cycle equal 8 basic clock fc.

1 instructure cycle = 8 / fc

TIMING GENERATOR AND TIME BASE

The timing generator produces the system clock from basic clock pulse which can be normal mode or slow

mode clock.

1 instruction cycle = 8 basic clock pulses

There are 22 stages time base .

When working in the single clock mode, the timebase clock source is come from fc that is RC oscillation.

Time base provides basic frequency for following function:

1. TBI (time base interrupt) .

2. Timer/counter, internal clock source.

3. Warm-up time for sleep - mode releasing.

TIME BASE INTERRUPT (TBI )

The time base can be used to generate a fixed frequency interrupt . There are 8 kinds of frequencies can be

selected by setting "25"

Single clock mode

P25 3

2

1

0

( initial value 0000 )

0 0 x x: Interrupt disable

1 0 x x: Reserved