EM63A165
EtronTech
Write Burst Length (A9)
•
This bit is used to select the write burst mode. When the A9 bit is "0", the Burst-Read-Burst-Write mode is
selected. When the A9 bit is "1", the Burst-Read-Single-Write mode is selected.
Table 11. Write Burst Length
A9
0
Write Burst Mode
Burst-Read-Burst-Write
Burst-Read-Single-Write
1
Note: A10 and BA0, 1 should stay “L” during mode set cycle.
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.
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
Burst
Stop
READ A
NOP
NOP
NOP
NOP
NOP
NOP
NOP
COMMAND
The burst ends after a delay equal to the CAS# Latency
CAS# Latency=2
DOUT A0
DOUT A1
DOUT A0
DOUT A2
DOUT A1
DOUT A3
DOUT A2
t
CK2, DQ
CAS# Latency=3
CK3, DQ
DOUT A3
t
Figure 17. Termination of a Burst Read Operation
＞
(Burst Length 4, CAS# Latency = 2, 3)
T0
T1
T2
T3
T4
T5
T6
T7
T8
CLK
Burst
Stop
NOP
WRITE A
DIN A0
NOP
NOP
NOP
NOP
NOP
NOP
COMMAND
don’t care
DIN A1
DIN A2
DQ
Figure 18. Termination of a Burst Write Operation
(Burst Length = X)
Rev. 2.2
15
Dec. /2013
ETRON [ ETRON TECHNOLOGY, INC. ]
