Cyclone® V Device Handbook: Volume 1: Device Interfaces and Integration

ID 683375
Date 10/18/2023
Public
Document Table of Contents

9.3. Performing BST

You can issue BYPASS, IDCODE, and SAMPLE JTAG instructions before, after, or during configuration without having to interrupt configuration.

To issue other JTAG instructions, follow these guidelines:

  • To perform testing before configuration, hold the nCONFIG pin low.
  • To perform BST during configuration, issue CONFIG_IO JTAG instruction to interrupt configuration. While configuration is interrupted, you can issue other JTAG instructions to perform BST. After BST is completed, issue the PULSE_CONFIG JTAG instruction or pulse nCONFIG low to reconfigure the device.

The chip-wide reset (DEV_CLRn) and chip-wide output enable (DEV_OE) pins on Cyclone® V devices do not affect JTAG boundary-scan or configuration operations. Toggling these pins does not disrupt BST operation (other than the expected BST behavior).

If you design a board for JTAG configuration of Cyclone® V devices, consider the connections for the dedicated configuration pins.