128Mb: x4, x8, x16
SDRAM
NOTE (continued):
4. AUTO REFRESH, SELF REFRESH and LOAD MODE REGISTER commands may only be issued when all banks are idle.
5. A BURST TERMINATE command cannot be issued to another bank; it applies to the bank represented by the current
state only.
6. All states and sequences not shown are illegal or reserved.
7. READs or WRITEs to bank m listed in the Command (Action) column include READs or WRITEs with auto precharge
enabled and READs or WRITEs with auto precharge disabled.
8. CONCURRENT AUTO PRECHARGE: Bank n will initiate the auto precharge command when its burst has been
interrupted by bank m’s burst.
9. Burst in bank n continues as initiated.
10. For a READ without auto precharge interrupted by a READ (with or without auto precharge), the READ to bank m
will interrupt the READ on bank n, CAS latency later (Figure 7).
11. For a READ without auto precharge interrupted by a WRITE (with or without auto precharge), the WRITE to bank m
will interrupt the READ on bank n when registered (Figures 9 and 10). DQM should be used one clock prior to the
WRITE command to prevent bus contention.
12. For a WRITE without auto precharge interrupted by a READ (with or without auto precharge), the READ to bank m
will interrupt the WRITE on bank n when registered (Figure 17), with the data-out appearing CAS latency later. The
last valid WRITE to bank n will be data-in registered one clock prior to the READ to bank m.
13. For a WRITE without auto precharge interrupted by a WRITE (with or without auto precharge), the WRITE to bank m
will interrupt the WRITE on bank n when registered (Figure 15). The last valid WRITE to bank n will be data-in
registered one clock prior to the READ to bank m.
14. For a READ with auto precharge interrupted by a READ (with or without auto precharge), the READ to bank m will
interrupt the READ on bank n, CAS latency later. The PRECHARGE to bank n will begin when the READ to bank m is
registered (Figure 24).
15. For a READ with auto precharge interrupted by a WRITE (with or without auto precharge), the WRITE to bank m will
interrupt the READ on bank n when registered. DQM should be used two clocks prior to the WRITE command to
prevent bus contention. The PRECHARGE to bank n will begin when the WRITE to bank m is registered (Figure 25).
16. For a WRITE with auto precharge interrupted by a READ (with or without auto precharge), the READ to bank m will
interrupt the WRITE on bank n when registered, with the data-out appearing CAS latency later. The PRECHARGE to
bank n will begin after tWR is met, where tWR begins when the READ to bank m is registered. The last valid WRITE to
bank n will be data-in registered one clock prior to the READ to bank m (Figure 26).
17. For a WRITE with auto precharge interrupted by a WRITE (with or without auto precharge), the WRITE to bank m will
interrupt the WRITE on bank n when registered. The PRECHARGE to bank n will begin after tWR is met, where tWR
begins when the WRITE to bank m is registered. The last valid WRITE to bank n will be data registered one clock prior
to the WRITE to bank m (Figure 27).
128Mb: x4, x8, x16 SDRAM
128MSDRAM_E.p65 – Rev. E; Pub. 1/02
Micron Technology, Inc., reserves the right to change products or specifications without notice.
©2001, Micron Technology, Inc.
32
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