The unused pins on EMIF bank can not work normally as GPIO
Hi,
My environment: 10AS016E4F29, with Quartus pro 22.4.
Today I met a problem.
In my design, we used the DDR4 chip, the EMIF IP locates on bank 2J and 2K. and then I assigned some unused pins on bank 2K for general purpose.
For example, below 7 pins are used for LED flashing to indicate some status of internal logic.
LED0_FPGA_HEART_1V2
LED1_HPS_UBOOT_1V2
LED2_HPS_UBOOT_1V2
LED3_HPS_APP_1V2
LED4_HPS_APP_1V2
LED5_HPS_HEART_1V2
LED6_HPS_OS_1V2
On top file, I write a module to generate a low frequency pulse which is used to flash the LEDs. And the I assigned this pulse to the LEDs, as below shows.
Per my test, the LEDs I listed above which locate on 2K bank can’t flash, but other LEDs on other bank can be flashed with the same signal driving.
Below is the pin assignment for your information.
Then I did some test for this issue.
If I instantiate the EMIF, these LEDs will always light even I send the low frequency pulse to drive them.
But if I delete the EMIF, these LEDs then can be driven to flashing by the same pulse.
in face i have discussed this topic with Richard by mails because he gave me strong support on other topics, but I would like to open a new case here for this topic to let you know the workload of your supporting team.
I don’t know if there is any coupling between the EMIF pins and the LED pins, although they locate in the same bank.
I remember the unused pins in the EMIF bank can be used as GPIO.
How can I control the LED normally with the EMIF instantiated in my system?
Very thanks for your support!
hi, FvM,
thank you for the reply.
yes, when I disable the EMIF, the pins can be driven normally. when I enable the EMIF, the pins can not be driven by logic.
and i also found an Article with ID 000079165 from intel website, it mentioned that if HPS EMIF is enabled, Lane 3 of bank 2K can only be used as FPGA input only. I think this is the root cause.
But the article also mentioned that the Quartus Prime software version 15.1.1 and earlier do not check for these restrictions, and the patch for above restriction is also scheduled to be added to a future version of the Quartus Prime software. I used Quartus pro 22.4, the newest, it seems this version still not check this rectriction.
thanks again!
Rain.