TMS626812B Datasheet, PDF (4/40 Pages) Texas Instruments – 1,048,576 BY 8-BIT BY 2-BANK SYNCHRONOUS DYNAMIC RANDOM-ACCESS MEMORIES

TMS626812B
1 048 576 BY 8-BIT BY 2-BANK
SYNCHRONOUS DYNAMIC RANDOM-ACCESS MEMORIES
SMOS693A – OCTOBER 1997 – REVISED APRIL 1998
operation (continued)
Table 2. Clock-Enable (CKE) Command Function Table^†
COMMAND‡
CKE CKE
CS
RAS CAS
W
STATE OF BANK(S)
(n – 1)
(n)
(n)
(n)
(n)
(n) ^MNEMONIC
Self-refresh entry
T = deac
B = deac
H
L
L
L
L
H
SLFR
Power-down entry on cycle (n+1)§
T = no access operation¶
B = no access operation¶
H
L
X
X
X
X
PDE
Self-refresh exit
T = self-refresh
L
H
L
H
H
H
—
B = self-refresh
L
H
H
X
X
X
—
Power-down exit#
T = power down
B = power down
L
H
X
X
X
X
—
CLK suspend on cycle (n+1)
T = access operation¶
B = access operation¶
H
L
X
X
X
X
HOLD
CLK suspend exit on cycle (n+1)
T = access operation¶
B = access operation¶
L
H
X
X
X
X
—
† _{For execution of these commands, A0 – A11(n) and DQM(n) are don’t care entries.}
‡ _{All other unlisted commands are considered as vendor-reserved or illegal commands.}
§ _{On cycle n, the device executes the respective command (listed in Table 1). On cycle (n+1), the device enters power-down mode.}
¶ _{A bank is no longer in an access operation one cycle after the last data-out cycle of a read operation, and two cycles after the last data-in cycle}
of a write operation. Neither the PDE nor the HOLD command is allowed on the cycle immediately following the last data-in cycle of a write
operation.
# _{If setup time from CKE high to the next CLK high satisfies tCESP , the device executes the respective command (listed in Table 1). Otherwise,}
either the DESL or the NOOP command must be applied before any other command.
Legend:
n = CLK cycle number
L = Logic low
H = Logic high
X = Don’t care, either logic low or logic high
T = Bank T
B = Bank B
deac = Deactivated
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