M53D2561616A-2F Datasheet, PDF (29/47 Pages) Elite Semiconductor Memory Technology Inc. – Bi-directional data strobe (DQS)

ESMT
M53D2561616A (2F)
2. DESELECT and NOP are functionally interchangeable.
3. All states and sequences not shown are illegal or reserved.
4. This command may or may not be bank specific. If all banks are being precharged, they must be in a valid state for
precharging.
5. The new Read or Write command could be Auto Precharge enabled or Auto Precharge disabled.
6. Current State Definitions:
Idle: The bank has been precharged, and t_RP has been met.
Row Active: A row in the bank has been activated, and t_RCD has been met. No data bursts / accesses and no register accesses
are in progress.
Read: A READ burst has been initiated, with Auto Precharge disabled, and has not yet terminated or been terminated.
Write: a WRITE burst has been initiated, with Auto Precharge disabled, and has not yet terminated or been terminated.
7. The following states must not be interrupted by a command issued to the same bank. DESELECT or NOP commands or
allowable commands to the other bank should be issued on any clock edge occurring during these states. Allowable
commands to the other bank are determined by its current state and the part of Command to Bank n, according to the part of
Command to Bank m.
Precharging: starts with the registration of a PRECHARGE command and ends when t_RP is met. Once t_RP is met, the bank will
be in the idle state.
Row Activating: starts with registration of an ACTIVE command and ends when t_RCD is met. Once t_RCD is met, the bank will be
in the ‘row active’ state.
Read with AP Enabled: starts with the registration of the READ command with Auto Precharge enabled and ends when t_RP
has been met. Once t_RP has been met, the bank will be in the idle state.
Write with AP Enabled: starts with registration of a WRITE command with Auto Precharge enabled and ends when t_RP has
been met. Once t_RP is met, the bank will be in the idle state.
8. The following states must not be interrupted by any executable command; DESELECT or NOP commands must be applied to
each positive clock edge during these states.
Refreshing: starts with registration of an AUTO REFRESH command and ends when t_RFC is met. Once t_RFC is met, the device
will be in an ‘all banks idle’ state.
Accessing Mode Register: starts with registration of a MODE REGISTER SET command and ends when t_MRD has been met.
Once t_MRD is met, the device will be in an ‘all banks idle’ state.
Precharging All: starts with registration of a PRECHARGE ALL command and ends when t_RP is met. Once t_RP is met, the bank
will be in the idle state.
9. Not bank-specific; requires that all banks are idle and no bursts are in progress.
10. Not bank-specific. BURST TERMINATE affects the most recent read burst, regardless of bank.
11. Requires appropriate DM masking.
12. A WRITE command may be applied after the completion of data output, otherwise a BURST TERMINATE command must be
issued to end the READ prior to asserting a WRITE command.
13. Read with AP enabled and Write with AP enabled: the Read with Auto Precharge enabled or Write with Auto Precharge
enabled states can be broken into two parts: the access period and the precharge period. For Read with AP, the precharge
period is defined as if the same burst was executed with Auto Precharge disabled and then followed with the earliest possible
PRECHARGE command that still accesses all the data in the burst. For Write with AP, the precharge period begins when t_WR
ends, with t_WR measured as if Auto Precharge was disabled. The access period starts with registration of the command and
ends where the precharge period (or t_RP) begins. During the precharge period of the Read with AP enabled or Write with AP
enabled states, ACTIVE, PRECHARGE, READ, and WRITE commands to the other bank may be applied; during the access
period, only ACTIVE and PRECHARGE commands to the other banks may be applied. In either case, all other related
limitations apply (e.g. contention between READ data and WRITE data must be avoided).
14. AUTO REFRESH, SELF REFRESH, and MODE REGISTER SET commands may only be issued when all bank are idle.
15. A BURST TERMINATE command cannot be issued to another bank; it applies to the bank represented by the current state
only.
16. READs or WRITEs listed in the Command column include READs and WRITEs with Auto Precharge enabled and READs and
WRITEs with Auto Precharge disabled.
Elite Semiconductor Memory Technology Inc.
Publication Date : Feb. 2014
Revision : 1.1
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