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手册的第178页对EMC的address mapping是这样写的
32 bit external bus address mapping (Row, Bank, Column)
1 0 000 00 16 Mb (2Mx8), 2 banks, row length = 11, column length = 9
1 0 000 01 16 Mb (1Mx16), 2 banks, row length = 11, column length = 8
1 0 001 00 64 Mb (8Mx8), 4 banks, row length = 12, column length = 9
1 0 001 01 64 Mb (4Mx16), 4 banks, row length = 12, column length = 8
1 0 001 10 64 Mb (2Mx32), 4 banks, row length = 11, column length = 8
1 0 010 00 128 Mb (16Mx8), 4 banks, row length = 12, column length = 10
1 0 010 01 128 Mb (8Mx16), 4 banks, row length = 12, column length = 9
1 0 010 10 128 Mb (4Mx32), 4 banks, row length = 12, column length = 8
1 0 011 00 256 Mb (32Mx8), 4 banks, row length = 13, column length = 10
1 0 011 01 256 Mb (16Mx16), 4 banks, row length = 13, column length = 9
1 0 011 10 256 Mb (8Mx32), 4 banks, row length = 13, column length = 8
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 external bus 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
我的问题是
1。为什么会是同样是32位总线的,一种内存分成两个配置?
2。同样的bank,同样的row,同样的column,同样的32位数据宽度,为什么有不一样的容量?
1 0 001 00 64 Mb (8Mx8), 4 banks, row length = 12, column length = 9
1 0 010 01 128 Mb (8Mx16), 4 banks, row length = 12, column length = 9
3。容量计算与手册不符合,比如
1 0 010 01 128 Mb (8Mx16), 4 banks, row length = 12, column length = 9
按这个规格算出来的容量应该是256Mb才是正确。
4。1 0 010 01 128 Mb (8Mx16), 4 banks, row length = 12, column length = 9
这个例子中8M*16中的16代表何意?难道是指内存的数据总线宽度,但想想又不对啊,
这个明明是属于32 bit external bus address mapping 里的啊,怎么又变成16位的呢
迷糊求解。
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