C51的XTAL1,XTAL2的外接电源经验

1.XTAL1 XTAL2 外接由两个电容与晶振的并联谐振时钟电路

C1,C2 选30pF,晶振选1.2-12MHz,设计时,当使晶振各电容尽可能的与C51单片机靠近,以保证稳定可靠

2.或用外部振荡器接至XTAL2,XTAL1接地,注意:XTAL1如果不接地的话,Electrical Rule Check会给出错误如下下:

ELECTRICAL RULES CHECK REPORT
=============================
Design: D:\proteus-design\yx-design\IO-1.DSN
Doc. no.:
Revision:
Author:
Created: 07/02/06
Modified: 07/02/06

UNDRIVEN: U1,XTAL1 (Input)

Netlist generated OK.
ERC errors found.