

AR# 992

XC5200 JTAG - Sample/Preload in a XC5200 appears to work like BYPASS


General Description:

After loading the SAMPLE/PRELOAD instruction in a 5K device, the

data being shifted in to the device starts appearing on the TDO pin

one TCK later. In other words, the SAMPLE/PRELOAD instruction appears

to work like the BYPASS instruction.

All other instructions appear to work correctly.


If the XC5200 /PROGRAM pin is held low, the SAMPLE/PRELOAD instruction

can not be executed. Before executing boundary scan instructions

in the XC5200, make sure that the /PROG pin is not held low.

AR# 992
日期 05/07/2014
状态 Archive
Type 综合文章