EtronTech
EM636165
1M x 16 SDRAM
Test Mode field (A8~A7)
·
These two bits are used to enter the test mode and must be programmed to "00" in normal
operation.
A8
0
A7
0
Test Mode
normal mode
0
1
Vendor Use Only
Vendor Use Only
1
X
Single Write Mode (A9)
·
This bit is used to select the write mode. When the BS bit is "0", the Burst-Read-Burst-
Write mode is selected. When the BS bit is "1", the Burst-Read-Single-Write mode is
selected.
A9
0
Single Write Mode
Burst-Read-Burst-Write
Burst-Read-Single-Write
1
Note: A10 and A11 should stay “L” during mode set cycle.
8
9
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.
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
NOP
NOP
NOP
COMMAND
NOP
NOP
Burst Stop
DOUT A
NOP
NOP
The burst ends after a delay equal to the CAS# latency.
CAS# latency=1
DOUT A
DOUT A
DOUT A
0
1
2
3
t
, DQ's
CK1
CAS# latency=2
, DQ's
DOUT A
DOUT A
DOUT A
2
DOUT A
3
0
1
t
CK2
CAS# latency=3
, DQ's
DOUT A
0
DOUT A
DOUT A
DOUT A
3
1
2
t
CK3
Termination of a Burst Read Operation
＞
4, CAS# Latency = 1, 2, 3)
(Burst Length
Preliminary
15
Rev. 2.7 Mar. 2006
ETRON [ ETRON TECHNOLOGY, INC. ]
