regards:

here we have 2 case.

---------------------------------------------- case1: we connect WR pin of 8051 to

(1)CH375 we can successfully read the flash disk. ---------------------------------------------- case2: we connect WR pin of 8051 to (1)CH375 (2)CPLD use CPLD to drive the LED. then we "cannot" successfully read the flash disk. --------------------------------------------------- we measure the WR signal of 2 case.

WR(CASE1)is bigger then WR(CASE2),there seems a problem of "fan-out" problem. when the 8051's WR drive 2 chip,the amplitude of WR is smaller.Then we cannot use the CH375 correctly.Is there any good suggestion to do ,such that we can use the CH375 and CPLD correctly at the same time.

best regards to WCH ------------------------------------------------------------------------------------------ Ownway Technology Liu Kang Ming Mobile:0922-098-061 TEL：+886-3-5385328#6811 FAX：+886-3-5385705 E-mail 1 : 个人信息保护，已隐藏 E-mail 2 : 个人信息保护，已隐藏 Address : 6F, No.18.,Lane 522, Section 5 , Chung Haw Road , Hsinchu , Taiwan R.O.C

按照你上面所说的话,那估计需要看下你的原理图来确定下是什么问题,这个一般出现在硬件问题,包括硬件冲突.

regards: our hardware schematic is attached.

we add two wire(WR,ALE) to cpld then we cannot successfully read the CH375's disk.

best regards to wch.

是中国人说什么洋话！