Forum Discussion

Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
14 years ago

JTAG chain with Cyclone V, MAX V, and Texas Instruments AM3559.

Hi My board will have three JTAG devices: Cyclone V, MAX V, and Texas Instruments AM3559. I would like to make a JTAG chain with these 3 devices. Will it work? I have seen that this chain i...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
14 years ago

You need to ensure that your JTAG I/O voltages match up between devices.

Also a good idea to buffer your TMS and TCK signals.

I have done this myself with multiple Altera FPGAs and Analog Devices SHARCs and it works fine. I did have some trouble early on but it was mainly down to (lack of) consideration of the power sequencing of the SHARC and TRST wiring.

Also, make sure you read the relevant handbooks for JTAG wiring schemes.