How do I read the USERCODE instruction out of Altera devices that support it without using a JAM File or JAM Byte-Code File? - How do I read the USERCODE instruction out of Altera devices that support it without using a JAM File or JAM Byte-Code File? Description The USERCODE instruction can be read out of devices simply by loading the JTAG instruction register with the USERCODE instruction and shifting out the 32-bit code. Reading the USERCODE instruction out of a device is a relatively simple JTAG process. Below is psuedocode that summarizes the process: Traverse the JTAG state machine to the Shift-IR state Load the USERCODE instruction Traverse the JTAG state machine to the Shift-DR state Shift out the 32-bit USERCODE value The easiest way is to obtain the USERCODE is to use Jam™ Files or Jam Byte-Code Files, especially for embedded systems that already implement a Jam Player. The Jam language provides an easy interface to the JTAG port. Refer to the device family data sheets for information on which devices support the USERCODE instruction. Related Articles Can the user design logic access the JTAG USERCODE register that is loaded into the FPGA? Custom Fields values: ['novalue'] Troubleshooting novalue False ['novalue'] ['novalue'] novalue novalue ['Programmable Logic Devices'] ['novalue'] ['novalue'] ['novalue']