Digi NS9750 Computer Hardware User Manual


 
Registers
228
NS9750 Hardware Reference
A chip select can be connected to a single memory device; in this situation, the chip
select data bus width is the same as the device width. As an alternative, the chip
select can be connected to a number of external devices. In this situation, the chip
select data bus width is the sum of the memory device databus widths.
Examples
1 0 100 00
512 Mb (64Mx8), 4 banks, row length=13, column length=11
1 0 100 01
512 Mb (32Mx16), 4 banks, row length=13, column length=10
32-bit extended bus low-power SDRAM address mapping (bank, row, column)
1 1 000 00
16 Mb (2Mx8), 2 banks, row length=11, column length=9
1 1 000 01
16 Mb (1Mx16), 2 banks, row length=11, column length=8
1 1 001 00
64 Mb (8Mx8), 4 banks, row length=12, column length=9
1 1 001 01
64 MB (4Mx16), 4 banks, row length=12, column length=8
1 1 001 10
64 Mb (2Mx32), 4 banks, row length=11, column length=8
1 1 010 00
128 Mb (16Mx8), 4 banks, row length=12, column length=10
1 1 010 01
128 Mb (8Mx16), 4 banks, row length=12, column length=9
1 1 010 10
128 Mb (4Mx32), 4 banks, row length=12, column length=8
1 1 011 00
256 Mb (32Mx8), 4 banks, row length=13, column length=10
1 1 011 01
256 Mb (16Mx16), 4 banks, row length=13, column length=9
1 1 011 10
256 Mb (8Mx32), 4 banks, row length=13, column length=8
1 1 100 00
512 Mb (64Mx8), 4 banks, row length=13, column length=11
1 1 100 01
512 Mb (32Mx16), 4 banks, row length=13, column length=10
For a chip select connected to Select this mapping
32-bit wide memory device 32-bit wide address mapping
16-bit wide memory device 16-bit wide address mapping
4 x 8-bit wide memory devices 32-bit wide address mapping
2 x 8-bit memory devices 16-bit wide address mapping
[14] [12] [11:9] [8:7] Description
Table 157: Address mapping