Preliminary Datasheet
Burst Length and Burst Type
64Mbit – Enhanced SDRAM
8Mx8, 4Mx16 ESDRAM
Bursting provides a constant flow of data to memory locations (writes), or from memory locations (reads). Burst length
and burst type are programmable through address bits A0-A3 during a Mode Register Set command.
Burst length defines the number of bits transferred after a Read or Write command. This value is programmable to one,
two, four, eight, or full page (actual page length is dependent on device organization: x8 or x16). Full page bursting is
only available with sequential type bursts. A burst does not automatically terminate in full page mode, but continues even
after the page length is satisfied.
Burst type defines the order in which the data is transferred. Both sequential and interleaved bursting is supported. For
details see the table below.
Burst Length and Type
Burst Length
2
Starting Address (A2 A1 A0)
xx0
xx1
x00
4
x01
x10
x11
000
001
010
8
011
100
101
110
111
Full Page (Note)
nnn
Sequential Addressing (decimal)
0, 1
1, 0
0, 1, 2, 3
1, 2, 3, 0
2, 3, 0, 1
3, 0, 1, 2
0, 1, 2, 3, 4, 5, 6, 7
1, 2, 3, 4, 5, 6, 7, 0
2, 3, 4, 5, 6, 7, 0, 1
3, 4, 5, 6, 7, 0, 1, 2
4, 5, 6, 7, 0, 1, 2, 3
5, 6, 7, 0, 1, 2, 3, 4
6, 7, 0, 1, 2, 3, 4, 5
7, 0, 1, 2, 3, 4, 5, 6
Cn, Cn+1, Cn+2, …
Interleaved Addressing (decimal)
0, 1
1, 0
0, 1, 2, 3
1, 0, 3, 2
2, 3, 0, 1
3, 2, 1, 0
0, 1, 2, 3, 4, 5, 6, 7
1, 0, 3, 2, 5, 4, 7, 6
2, 3, 0, 1, 6, 7, 4, 5
3, 2, 1, 0, 7, 6, 5, 4
4, 5, 6, 7, 0, 1, 2, 3
5, 4, 7, 6, 1, 0, 3, 2
6, 7, 4, 5, 2, 3, 0, 1
7, 6, 5, 4, 3, 2, 1, 0
Not Supported
Note: Page length is a function of I/O organization and column addressing.
x8 organization (CA0-CA8); Page Length = 512 column addresses
x16 organization (CA0-CA7); Page Length = 256 column addresses
This is a product in sampling or pre-production phase of development. Charac-
teristic data and other specifications are subject to change without notice.
Enhanced Memory Systems Inc., 1850 Ramtron Dr., Colo Spgs, CO 80921
PHONE: (800) 545-DRAM; FAX: (719) 488-9095;
http://www.edram.com
Revision 1.1
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RAMTRON [ RAMTRON INTERNATIONAL CORPORATION ]
