Altera_Forum
Honored Contributor
Honored ContributornSTATUS and CONF_DONE in user-mode
Can I toggle nSTATUS and/or CONF_DONE configuration signals after PS-configuration in user-mode?
Forum Discussion
7 Replies
Altera_Forumno, they are both dedicated configuration pins (on CIII at least)
- Altera_Forum
What will be, if nSTATUS and/or CONF_DONE is pulled down after configuration (in user mode)?
- Altera_Forum
i think i misunderstood your original question, the FPGA cannot drive nSTATUS or CONF_DONE, but your PS controller should control the signals according to the configuration chapter of the device handbook
- Altera_Forum
In handbook nothing said about this: What will be, if nSTATUS and/or CONF_DONE is pulled down after configuration (in user mode)?
- Altera_Forum--- Quote Start --- In handbook nothing said about this --- Quote End --- It's mentioned in the configuration handbook under device configuration pins.: Driving the pins low for a configured device is ignored.
- Altera_Forum
Thank You!
For CycloneIII on pg. 595 of “config_handbook.pdf” (Table 9–22): --- Driving nSTATUS low after configuration and initialization does not affect the configured device. …device ignores transitions on nSTATUS in user mode… After all configuration data is received without error and the initialization cycle starts, the target device releases CONF_DONE. Driving CONF_DONE low after configuration and initialization does not affect the configured device. --- But for nCE: “However, all user IO pins will be held in tri-state whilst nCE is pulled high during user mode.” (Solution ID: rd01102011_672) - Altera_Forum--- Quote Start --- However, all user IO pins will be held in tri-state whilst nCE is pulled high during user mode. --- Quote End --- The statement can't be found in regular Altera documents, and at least isn't correct for all devices. I guess, it's simply erroneous. nCE is e.g. used to enable external access to a connected AS flash. You won't want other pins than the AS connected pins tristated in this case, and as far as I experienced, they aren't.
