SPEC7 SN05 FLASH programming

SPEC7 SN05 is a v2.0 SPEC7 that was used to verify the prototype v3.0 heat-sink. The V2.0 heat-sink was removed in order to do so. After that it was found that FLASH programming failed. Most probably this is caused by a tiny crumble of copper from the heat-sink split pin hole which made a short circuit under SPI FLASH chip U10 (MT25QL256ABA8E12-1SIT).

U10 on SPEC7 SN05 was replaced but FALSH programming still failed in Vivado which complained about the FPGA being in NOR mode, rather than in JTAG mode although all DIP switches were in JTAG mode (actually the DIP switch was removed to fit the V3.0 heat-sink).

Investigation pointed put that the voltage at the DIP switch side of R218 was 0V while the voltage at the FPGA side (pin D25) was 0,7V. Apparently R218 was not pulling D25 low enough, therefore R218 on SPEC7 SN05 was replaced by a 10K resistor.