7220 datasheet(127/303 Pages) RENESAS

Part #	7220

Description	8-BIT SINGLE-CHIP MICROCOMPUTER

PDF	303 Pages

Scroll/Zoom	100%

Manufacturer	RENESAS [Renesas Technology Corp]

Direct Link	http://www.renesas.com

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127 / 303 page

2-100

7220 Group User’s Manual

FUNCTIONAL DESCRIPTION

2.16 Clock generating circuit

Fig. 2.16.1 Clock generating circuit block diagram

2.16 Clock generating circuit

Oscillation circuit consists of an “oscillation gate” which operates as an amplifier to provide the gain required

for oscillation and an “oscillating control flip-flop” to control this. Because of that, it is possible to start and

stop oscillating as required. For details concerning start and stop of oscillation, refer to “2.14 Low-power

dissipation mode.” Figure 2.16.1 shows the clock generating circuit block diagram.

Interrupt request

Interrupt disable

flag I

Reset

STP instruction

WIT

instruction

STP

instruction

Reset

Internal clock

1/2

1/8

Timer 3

Timer 4

XOUT

XIN

T34M0

T34M2

Selection gate :

Connected to black

side at reset.

T34M : Timer 34 mode register

7220 Datasheet(PDF) 127 Page - Renesas Technology Corp