183
4.17 Bus Timing
[Explanation of operation]
•
Write control is performed with only the CAS control signals (including CASL and CASH)
while RAS is lowered to "L", and then WE (including WEL and WEH) is lowered to "L".
•
Column addresses and output data are output in Q4 and Q5 cycles.
❍
CS area (CS4/CS5) switch-over in high-speed page mode, read and write combination,
2CAS/1WE
Figure 4.17-27 Example 3 of DRAM Interface Timing Chart in High-Speed Page Mode
[Explanation of operation]
•
Even if the CS area is switched, RAS remains at "L" in high-speed page mode.
•
When a bus cycle starts from a high-speed page, RDX in a read cycle goes down to "L" from
the rising edge of Q4 and is negated when the Q5 cycle ends. In a write cycle, it goes down
to "L" from the rising edge of WE (including WEL and WEH) Q4 and is negated when the Q5
cycle ends.
•
CS4X and CS5X change at the same time as the output address. When a bus cycle starts
from a high-speed page, they change from the Q4 cycle as with the column address.
Q4
CLK
A24-00
CS5X col.adr
CS5X col.adr
CS5X col.adr
CS4X col.adr
CS4X col.adr
D31-24
Write
D23-16
Read
Write
CS4X
CS5X
RDX
CS4:RAS
CS4:CASL
CS4:CASH
CS4:WE
CS5:RAS
CS5:CASL
CS5:CASH
CS5:WE
CS5 area
Q5
Q4
Q5
Q4
Q5
Q4
Q5
Q4
Q5
CS4 area
Idle
Read
Write
Write
Read
Read
Read
Read
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 ...
Page 460: ......
Page 461: ...FUJITSU SEMICONDUCTOR FR30 32 Bit Microcontroller MB91F109 Hardware Manual ...