EtronTech
9
4M x 32 LPSDRAM
EM669325
No-Operation command
(RAS# = "H", CAS# = "H", WE# = "H")
The No-Operation command is used to perform a NOP to the SDRAM which is selected (CS#
is Low). This prevents unwanted commands from being registered during idle or wait states.
10
Burst Stop command
(RAS# = "H", CAS# = "H", WE# = "L")
The Burst Stop command is used to terminate either fixed-length or full-page bursts. This
command is only effective in a read/write burst without the auto precharge function. The terminated
read burst ends after a delay equal to the CAS# latency (refer to the following figure). The
termination of a write burst is shown in the following figure.
T0
T1
T2
T3
T4
T5
T6
T7
T8
CLK
READ A
COMMAND
NOP
NOP
NOP
Burst Stop
NOP
NOP
NOP
NOP
The burst ends after a delay equal to the CAS# latency.
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
Termination of a Burst Read Operation (Burst Length
T0
CLK
T1
T2
T3
T4
T5
COMMAND
NOP
WRITE A
NOP
NOP
Burst Stop
NOP
CAS# latency= 2, 3
DQ's
DIN A0
DIN A1
DIN A2
don't care
Input data for the Write is masked.
Termination of a Burst Write Operation (Burst Length = X, CAS# Latency = 1, 2, 3)
Preliminary
13
＞
4, CAS# Latency = 2, 3)
T6
T7
T8
NOP
NOP
NOP
Rev 0.6
Sep. 2003
ETRON [ ETRON TECHNOLOGY, INC. ]
