Forum Discussion

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

JTAG Chain - which is which???

I am using Quartus2 web. My PCB has 2 blank MAX3000 CPLD's on it connected using JTAG chaining. Quartus shows both in the programmer but how do I know which is which.?They need to have different files loaded to them and I dont want to configure the wrong ones. I am concerned this would set some of the pins as ouputs when they should be inputs and cause damage to some of the devices on the board.

3 Replies

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    18 years ago

    I think, the devices are enumerated in programmer windows and selection menus in JTAG chain order.

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    18 years ago

    chain order - so is# 1 the one that the data goes into first or comes out of first?

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    18 years ago

    It must not be mentioned explicitely, that there would be many options to clear your doubts without damaging a device. However, in my imagination, water is flowing down, not upwards. So the data.