FUJITSU MB91F109 FR30 - Manual (Page 204)

180
CHAPTER 4 BUS INTERFACE
❍ Bus width: 16 bits, access: bytes
Figure 4.17-22 Example 2 of Usual DRAM Write Cycle Timing Chart
❍ Bus width: 8 bits, access: half-words
Figure 4.17-23 Example 3 of Usual DRAM Write Cycle Timing Chart
Q1 Q2 Q3 Q4 Q5 Q1 Q2 Q3 Q4 Q5
CLK
1)1CAS/2WE
A24-00 X #0 row.adr. #0 col.adr X #1 row.adr. #1 col.adr
D31-24 #0 X
D23-16 X #1
RAS
CAS
WEL
WEH
2)2CAS/1WE
A24-00 X #0 row.adr. #0 col.adr X #1 row.adr. #1 col.adr
D31-24 #0 #1
D23-16 X #1
RAS
CASL
CASH
WE
Upper address side
Lower address side
Upper address side
Lower address side
Q1 Q2 Q3 Q4 Q5 Q1 Q2 Q3 Q4 Q5
CLK
A24-00 X #0 row.adr. #0 col.adr X #1 row.adr. #1 col.adr
D31-24 #0 X
D23-16
RAS
CAS
WE