C51的XTAL1,XTAL2的外接电源经历:
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单片机接近,以确保安稳牢靠
2.或用外部振荡器接至XTAL2,XTAL1接地,留意:XTAL1假如不接地的话,Electrical Rule Check会给出过错如下下:
ELECTRICAL RULES CHECK REPORT
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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.