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Chapter 31 External Bus
9.SDRAM/FCRAM Interface Operation
Figure 9-7 Using 64 - Mbit SDRAM
When SDRAM modules are used with a total data width of 16 bits, SDRAMs No. 3 and No. 4 are not required and
DQ15 to DQ0 must be left open.
● Using 16 - bit SDRAM/FCRAM
Total data width of 32 bits: Use two or four SDRAM modules.
Total data width of 16 bits: Use one or two SDRAM modules.
Figure 9-8 shows how to use 64-Mbit SDRAM (two bank addresses and 12 row addresses).
A11-A0
This LSI
CS6
or
CS7
SCAS
SRAS
SWE
MCLKE
DQMUU
MCLKO DQ31-0
SDRAM(No.1)
CS CASRAS WE
CKE DQM CLK DQ7-DQ0
IA11-IA0
SDRAM(No.2)
CS
CASRAS WE
CKE DQM CLK
DQ7-DQ0
IA11-IA0
SDRAM(No.3)
CS CASRAS WE
CKE
DQM CLK DQ7-DQ0
IA11-IA0
SDRAM(No.4)
CS
CASRAS WE
CKE DQM CLK DQ7-DQ0
[7-0]
[31-24]
[23-16]
[15-8]
DQMUL
DQMLU
DQMLL
A14
BA
BA
BA
BA
IA11-IA0