SPRSP93 November 2024 F29H850TU , F29H859TU-Q1
ADVANCE INFORMATION
The EMIF memory controller is compliant with the JESD21-C SDR SDRAMs that use a 32-bit or 16-bit data bus. The EMIF has a single SDRAM chip select ( EMIF_CS[0]).
The address space of the EMIF, for the synchronous memory (SDRAM), lies beyond the 22-bit range of the program address bus and can only be accessed through the data bus, which places a restriction on the C compiler being able to work effectively on data in this space. Therefore, when using SDRAM, the user is advised to copy data (using the DMA) from external memory to RAM before working on it. See the examples in C2000Ware for C2000 MCUs and the F29H85x and F29P58x Real-Time Microcontrollers Technical Reference Manual.
SDRAM configurations supported are:
Additionally, the EMIF supports placing the SDRAM in self-refresh and power-down modes. Self-refresh mode allows the SDRAM to be put in a low-power state while still retaining memory contents because the SDRAM will continue to refresh itself even without clocks from the microcontroller. Power-down mode achieves even lower power, except the microcontroller must periodically wake up and issue refreshes if data retention is required. The EMIF module does not support mobile SDRAM devices.
On this device, the EMIF does not support burst access for SDRAM configurations. This means every access to an external SDRAM device will have CAS latency.