5.1.4 A_DIN and B_DIN
(Ask a Question)The required bits are LSb justified and unused MSb bits must be tied to 0. Two-port mode is in effect when the width of at least one port is greater than 20 bits, and A_DIN provides the MSb of the write-data while B_DIN provides the LSb of the write-data. The following table lists the data input buses for the two ports.
| Depth x Width | A_DIN/B_DIN | |
|---|---|---|
| Used Bits | Unused Bits (Must be tied to 0) | |
| 16K x 1 | [0] | [19:1] |
| 8K x 2 | [1:0] | [19:2] |
| 4K x 4 | [3:0] | [19:4] |
| 4K x 5 | [4:0] | [19:5] |
| 2K x 8 | [8:5] => [7:4], [3:0] => [3:0] | [19:9], [4] |
| 2K x 10 | [9:0] | [19:10] |
| 1K x 16 | [18:15] => [15:12] [13:10] => [11:8] [8:5] => [7:4] [3:0] => [3:0] | [19] [14] [9] [4] |
| 1K x 20 | [19:0] | None |
| 512 x 32 (two-port write) | A_DIN[18:15] => [31:28] A_DIN[13:10] => [27:24] A_DIN[8:5] => [23:20] A_DIN[3:0] => [19:16] B_DIN[18:15] => [15:12] B_DIN[13:10] =>[11:8] B_DIN[8:5] => [7:4] B_DIN[3:0] => [3:0] | A_DIN[19] A_DIN[14] A_DIN[9] A_DIN[4] B_DIN[19] B_DIN[14] B_DIN[9] B_DIN[4] |
| 512 x 40 (two-port write) | A_DIN[19:0] => [39:20] B_DIN[19:0] => [19:0] | None |
| 512 x 33 (two-port ECC) | A_DIN[15:0] => [32:17] B_DIN[16:0] => [16:0] | A_DIN[19:16] B_DIN[19:17] |