SDRAM
Austin Semiconductor, Inc.
AS4SD2M32
FIGURE 1: Mode Register Definition TABLE 1: Burst Definition
BURST
LENGTH
BA1
BA0
2
4
8
Full
Page
(y)
STARTING
ORDER OF ACCESSES WITHIN A BURST
COLUMN TYPE = SEQUENTIAL TYPE = INTERLEAVED
A0
0
0-1
0-1
1
1-0
1-0
A1 A0
0 0
0-1-2-3
0-1-2-3
0 1
1-2-3-0
1-0-3-2
1 0
2-3-0-1
2-3-0-1
1 1
3-0-1-2
3-2-1-0
A2 A1 A0
0 0 0
0-1-2-3-4-5-6-7
0-1-2-3-4-5-6-7
0 0 1
1-2-3-4-5-6-7-0
1-0-3-2-5-4-7-6
0 1 0
2-3-4-5-6-7-0-1-
2-3-0-1-6-7-4-5
0 1 1
3-4-5-6-7-0-1-2
3-2-1-0-7-6-5-4
1 0 0
4-5-6-7-0-1-2-3
4-5-6-7-0-1-2-3
1 0 1
5-6-7-0-1-2-3-4
5-4-7-6-1-0-3-2
1 1 0
6-7-0-1-2-3-4-5
6-7-4-5-2-3-0-1
1 1 1
7-0-1-2-3-4-5-6
7-6-5-4-3-2-1-0
Cn, Cn+1, Cn+2, Cn+3,
n=A0-A7
Cn+4…
Not Supported
(location 0-y)
…Cn-1,
Cn…
NOTES:
1. For full-page access: y=512
2. For a burst length of two, A1-A7 select the block-of-two burst;
A0 selects the starting column within the block.
3. For a burst length of four, A2-A7 select the block-of-four burst;
A0-A1 selects the starting column within the block.
4. For a burst length of eight, A3-A7 select the block-of-eight burst;
A0-A2 selects the starting column within the block.
5. For a full-page burst, the full row is selected and A0-A7 select the
starting column.
6. Whenever a boundary of the block is reached within a given
sequence above, the following access wraps within the block.
7. For a burst length of one, A0-A7 select the unique column to be
accessed, and mode register bit M3 is ignored.
AS4SD2M32
Rev. 1.0 1/08
Austin Semiconductor, Inc. reserves the right to change products or specifications without notice.
5
AUSTIN [ AUSTIN SEMICONDUCTOR ]
