tm
1
TE
CH
T431616D/E
Commands
BankPrecharge command
(RAS# = "L", CAS# = "H", WE# = "L", A11 = “V”, A10 = "L", A0-A9 = Don't care)
The BankPrecharge command precharges the bank disignated by A11 signal. The precharged bank is
switched from the active state to the idle state. This command can be asserted anytime after t
RAS
(min.) is satisfied
from the BankActivate command in the desired bank. The maximum time any bank can be active is specified by
t
RAS
(max.). Therefore, the precharge function must be performed in any active bank within t
RAS
(max.). At the
end of precharge, the precharged bank is still in the idle state and is ready to be activated again.
PrechargeAll command
(RAS# = "L", CAS# = "H", WE# = "L", A11 = Don't care, A10 = "H", A0-A9 = Don't care)
The PrechargeAll command precharges both banks simultaneously and can be issued even if both banks are
not in the active state. Both banks are then switched to the idle state.
Read command
(RAS# = "H", CAS# = "L", WE# = "H", A11= “V”, A9 = "L", A0-A7 = Column Address)
The Read command is used to read a burst of data on consecutive clock cycles from an active row in an
active bank. The bank must be active for at least t
RCD
(min.) before the Read command is issued. During read
bursts, the valid data-out element from the starting column address will be available following the CAS# latency
after the issue of the Read command. Each subsequent data-out element will be valid by the next positive clock
edge (refer to the following figure). The DQs go into high-impedance at the end of the burst unless other
command is initiated. The burst length, burst sequence, and CAS# latency are determined by the mode register,
which is already programmed. A full-page burst will continue until terminated (at the end of the page it will wrap
to column 0 and continue).
T0
T1
T2
T3
T4
T5
T6
T7
T8
2
3
CLK
COMMAND
READ A
NOP
NOP
NOP
NOP
NOP
NOP
NOP
NOP
CAS# latency=1
tCK1, DQ's
CAS# latency=2
tCK2, DQ's
CAS# latency=3
tCK3, DQ's
DOUT A0
DOUT A1
DOUT A2
DOUT A3
DOUT A0
DOUT A1
DOUT A2
DOUT A3
DOUT A0
DOUT A1
DOUT A2
DOUT A3
Burst Read Operation
(Burst Length = 4, CAS# Latency = 1, 2, 3)
TM Technology Inc. reserves the right
P. 6
to change products or specifications without notice.
Publication Date: FEB. 2007
Revision: A
TMT [ TAIWAN MEMORY TECHNOLOGY ]
