请教各位,在CHIPSCOPE中利用JTAG下载bit文件到xc3s1200E中,下载完成后出现如下错误,是什么原因?
ERROR: Internal Error: Failed reading JTAGInstruction Register.
ERROR: Configuration failed.
ERROR: No devices detected while scanning the JTAGchain
ERROR: Failed detecting JTAG device chain
1. JTAG链路中有三个器件:XCF04S, XC3S1200E and XC4SX55;
2. 将相应的bit文件下载到XC4SX55中,没有出错且工作正常;
3. 利用 iMPACT进行下载,显示program succeed,但马上就扫不到JTAG链路了;
4. 出现上述错误后,我量XC3S1200E的done管脚为高(2.5V);
5. 我用飞线修改JTAG链路,使XC4SX55不在链路中,XC3S1200E可正常加载且工作正常 |