SPRUI30H November 2015 – May 2024 DRA745 , DRA746 , DRA750 , DRA756
For EMIF_SDRAM_CONFIG[28:27] IBANK_POS = 0 and EMIF_SDRAM_CONFIG_2[27] EBANK_POS = 0, Table 15-85 lists which source address bits (MAddr) are mapped to the SDRAM row, column and bank bits for all combinations of IBANK and PAGESIZE.
MAddr[31:N] N = 1 if 16-bit data bus width; N = 2 if 32-bit data bus width | |||||
---|---|---|---|---|---|
row address | bank address | column address | |||
ROWSIZE value | row width (bits) | IBANK value | bank[2:0] width (bits) | PAGESIZE value | col width (bits) |
In this case the ROWSIZE bit field is not used | 16 | 0 | 0 | 0 | 8 |
1 | 1 | 1 | 9 | ||
2 | 2 | 2 | 10 | ||
3 | 3 | 3 | 11 |
The ROWSIZE bit field is unused in case of IBANK_POS = 0 and EBANK_POS = 0.
For EMIF_SDRAM_CONFIG[28:27] IBANK_POS = 0, the effect of the address-mapping scheme is that as the source address increments across the SDRAM pages, EMIF moves to page with the same number as in the previous bank. This movement across the banks continues until the same page is accessed in all banks and then EMIF moves to the next page in the first bank. The EMIF uses this movement across internal banks while remaining on the same page to maximize the number of the open SDRAM banks within the overall SDRAM space.
Thus, the EMIF can keep a maximum of 8 banks open at a time, and can interleave among all of them.