Answers Database XC4000 JTAG - Can boundary scan pins be used for JTAG and standard input/output at the same time? Record #170 Product Family: Hardware Product Line: 4000E Product Part: 4000E Problem Title: XC4000 JTAG - Can boundary scan pins be used for JTAG and standard input/output at the same time? Problem Description: Urgency: Standard General Description: XC4000: Can boundary scan pins be used for bscan and input at the same time? Solution 1: Even if the boundary scan symbol is used in a schematic, the input pins tms,tck,and tdi could still be used as inputs to be routed to internal logic. For customers who intend to use Boundary Scan instructions it is recommended to dedicate the pins for boundary scan use only and not to use them as inputs. However, for users who attempt this must be careful not to inadvertently force the chip into an undesired boundary scan state by applying other inputs to these pins. For further information on Boundary Scan feature in this product please refer to http://www.xilinx.com/xapp/xapp017.pdf End of Record #170 - Last Modified: 01/10/00 18:01

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