2024-08-12 07:50 AM
I'm using STM32H747i-DISCO board. In Stm32Cube_FW_H7_V1.11.2 STM32H747I-DISCO example project -- stm32h747i_discovery_sdram.c, cas is 3. SDRAM worked fine with this setting. It didn't work when I changed cas to 2. Datasheet of Is42s32800G-6BLI shows cas is 2 at 100MHz clock.
In How to set up the FMC peripheral to interface with the SDRAM...CAS is also set to 2 for FMC clock 100MHz. Why cas need to be 3 in Stm32Cube_FW_H7_V1.11.2 STM32H747I-DISCO example project?
2024-08-12 08:15 AM - edited 2024-08-12 08:18 AM
>>Why cas need to be 3 in Stm32Cube_FW_H7_V1.11.2 STM32H747I-DISCO example project?
Probably doesn't, but causes no harm, and provides more margin in the access timings, and perhaps others.
IS42S32800J-6BLI, perhaps check/confirm what's actually placed. https://www.issi.com/WW/pdf/42-45S32800J.pdf
Are you running at 400 or 480 MHz?