Intel mcs-48 manual Introduction, Crystal Oscillator Mode, Driving from External Source

APPLICATION EXAMPLES

5.0 Introduction

The following chapter is organized in two sections, Hardware and Software. The hardware section gives examples of some typical configurations of MCS-48 compon- ents while software section gives assembly language listings of some common appli- cations routines.

5.1 Hardware Examples

CRYSTAL OSCILLATOR MODE

	r-----	XTAll
	I
< 15 pF	I
	I
(INCLUDES XTAL,	L
SOC~ET, STRAY)	..
	I
	I
	IL ____ _

15-25pF I

(INCLUDES SOCKET, STRAY) ":'

CRYSTAL SERIES RESISTANCE SHOULD BE <7512 AT 6 MHz; <1601l AT 3.6 MHz.

DRIVING FROM EXTERNAL SOURCE

+5V

47012

Jo - 4 ------ '"2~ XTAll

+5V

47012

L---'--~XTAL2

BOTH XTAll AND XTAl2 SHOULD BE DRIVEN. RESISTORS TO Vee ARE NEEDED TO ENSURE V,H =3.8V

IF TTL CIRCUITRY IS USED.

NOTE:

A STANDARD SERIES RESONANT XTAL SUCH AS CTS KNIGHTS MP060 OR CRYSTEK CY6B WILL PROVIDE BETTER THAN .1% FRE· QUENCY ACCURACY.

EACH C SHOULD BE APPROXIMATELY 20pF,

INCLUDING STRAY CAPACITANCE. FOR

MORE INFORMATION ON XTALS SEE INTEl-

APPLICATION NOTE AP.35.

FREQUENCY REFERENCE OPTIONS

LC OSCILLATOR MODE

--"- J;.. NOMINAL'

45 .H 20 pF 5.2 MHz

12O.H 20pF 3.2 MHZ..--_..-_-42 XTAll

C' - C+3Cpp

- 2

L---_~_~3 XTAl2	Cpp " 5 - 10 pF PlN·TO·PIN
	CAPACITANCE

EACH C SHOULD BE APPROXIMATELY 20 pF. INCLUDING STRAY CAPACITANCE.

NOTE: SEE PAGE 5·3FOR 6021

FREQUENCY REFERENCES.

5·1