175
4.17 Bus Timing
4.17.9 Usual DRAM Interface: Write
This section provides a usual DRAM interface write timing chart.
■
Usual DRAM Interface: Write Timing Chart
❍
Bus width: 16 bits, access: words, CS4 area access
Figure 4.17-17 Example of Usual DRAM Interface Write Timing Chart
[Explanation of operation]
•
The output of A24 to A00 (address 24 to address 00) is similar to that at read cycles.
•
D31 to D16 (data 31 to data 16) represent write data to external memory and I/O. In write
cycles, write data is output from the Q1 cycle and set to High-Z when the Q5 cycle ends.
For the 1CAS/2WE, valid data is output while WEL corresponds to D31 to D24, and WEH
corresponds toD23 to D16. For the 2CAS/1WE, valid data is output while WE corresponds
to D31 to D16.
Q1
CLK
X
#0 row.adr.
#0 col.adr
X
#2 row.adr.
#2 col.adr
D31-24
#0
#2
D23-16
#1
#3
RAS
CAS
WEL
WEH
RDX
CS4X
(DACK0)
(EOP0)
X
#0 row.adr.
#0 col.adr
X
#2 row.adr.
#2 col.adr
D31-24
#0
#2
D23-16
#1
#3
RAS
CASL
CASH
WE
RDX
CS4X
(DACK0)
(EOP0)
Q2
Q3
Q4
Q5
Q1
Q2
Q3
Q4
Q5
A24-00
A24-00
Half-word access of
Half-word access of
upper address side
lower address side
1)1CAS/2WE
2)2CAS/1WE
Summary of Contents for MB91F109
Page 2: ......
Page 3: ...FUJITSU LIMITED FR30 32 Bit Microcontroller MB91F109 Hardware Manual ...
Page 4: ......
Page 10: ...vi ...
Page 24: ...xx ...
Page 96: ...72 CHAPTER 2 CPU ...
Page 224: ...200 CHAPTER 4 BUS INTERFACE ...
Page 234: ...210 CHAPTER 5 I O PORTS ...
Page 268: ...244 CHAPTER 9 U TIMER ...
Page 290: ...266 CHAPTER 10 UART ...
Page 314: ...290 CHAPTER 12 16 BIT RELOAD TIMER ...
Page 322: ...298 CHAPTER 13 BIT SEARCH MODULE ...
Page 392: ...368 CHAPTER 16 FLASH MEMORY ...
Page 432: ...408 APPENDIX E Instructions F Table E 2 Instruction Formats OP rel11 5 11 ...
Page 448: ...424 APPENDIX E Instructions ...
Page 449: ...425 INDEX INDEX The index follows on the next page This is listed in alphabetic order ...
Page 458: ...434 INDEX ...
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Page 461: ...FUJITSU SEMICONDUCTOR FR30 32 Bit Microcontroller MB91F109 Hardware Manual ...