topic MPC5675 EBI application issue in MPC5xxx

MPC5675 EBI application issue

GaoYuann — Thu, 07 Dec 2023 01:51:23 GMT

in our EBI application, we only used these low address pins (A27-A31), so we have designed the other unused addr pins as GPIO function.

so, in our software, we configured the EBI addr pins A27-A31 as EBI function, while A8-A26 as GPIO function.

the problem is that it would lead to a address-access-error-liking exception when CPU want to operate a EBI reading/writing. to fix this problem, i tried to configure all EBI addr pins as EBI function, and the issue got solved, meanwhile, the GPIO function can not work.

in our EBI usage, we only used a small number of addr pins, if the other ADDR pins can not be used as other functions, the pin resourse would get very strained.

can anybody help me with this problem?

thanks a lot.

Re: MPC5675 EBI application issue

davidtosenovjan — Thu, 07 Dec 2023 15:49:24 GMT

If you are using 8-bit data bus, this would be correct setting. However there are also data pins that is needed to use (can also be muxed with addresses).

Following signals are also routed to he same pins where adx is either address/data or data and addx are address lines only.

ad8-add24
ad9-add25
ad10-add26
ad11-add27
ad12-add28
ad13-add29
ad14-add30
ad15-add31

Pay attention to DBM bit in EBI_MCR. Only pins that are not used for any EBI purpose may be used as GPIO.

Could you show me you connection schematic (only EBI pins and memory)?

Re: MPC5675 EBI application issue

GaoYuann — Fri, 08 Dec 2023 06:54:59 GMT

thanks，david.

here is our EBI application schematic.