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FLASH-PROGRAMMER: Buffering JTAG signals: programming not working

Part Number: FLASH-PROGRAMMER
Other Parts Discussed in Thread: CC2640

Hello,

   We're building a production programmer where we need to switch the JTAG signals so we can have one XDS programmer talk to 5 different CC2640 targets. We're using a SN74LV4T125PWR buffer chip and controlling the Output Enable (OE) pin. We're getting errors when we go through the buffers. I've looked at buffer input (from XDS200) and buffer output (to target) on a scope and they look the same; good signal integrity on both sides. I even started playing with the JTAG clock speed in the XDS config files (C:\Program Files (x86)\Texas Instruments\SmartRF Tools\Flash Programmer 2\config\xds\board_config)

Do we need additional JTAG pull-ups/pull-downs on the programmer side of the buffer or the target side of the buffer? Currently there is none. If so, which JTAG signals get pulled up and which get pulled down?

Thanks,

Derek