Rainbow Electronics W90N745CDG - Manual (Page 64)

W90N745CD/W90N745CDG
Publication Release Date: September 22, 2006
- 59 - Revision A2
6.3.2.2. SDRAM Power Up Sequence
The SDRAM must be initialized predefined manner after power on.W90N745 SDRAM Controller
automatically executes the commands needed for initialion and set the mode register of each bank to
default value. The default value is：
— Burst Length = 1
— Burst Type = Sequential (fixed)
— CAS Latency = 2
— Write Burst Length = Burst (fixed)
The value of mode register can be changed after power up sequence by setting the value of
corresponding bank’s configuration register “LENGTH” and “LATENCY” bits and set the MRSET bit
enable to execute the Mode Register Set command.
6.3.2.3. SDRAM Interface
M C L K
M C K E
n S C S [1 :0 ]
n S R A S
n S C A S
n S W E
n S D Q M [1 :0 ]
A [2 0 :0 ]
D [1 5 :0 ]
A [1 0 :0 ]
D Q [[1 5 :0 ]
D Q M [1 :0 ]
n W E
n C A S
n R A S
n C S
B S 0
B S 1
C L K
C K E
W 9 0 N 7 4 5
A 1 3
A 1 4
A [1 0 :0 ]
n S C S 0
S D R A M
3 2 M b 5 1 2 K x 4 x 1 6
n S D Q M [1 :0 ]
Figure 6.3.1 SDRAM Interface