155
4.16 Relationship between Data Bus Widths and Control Signals
4.16.4 DRAM Relationships
This section explains the DRAM relationships.
■
DRAM Control Pins
Table 4.16-2 lists the relationship between the pin functions and bus widths used in the DRAM
interface.
Table 4.16-2 Functions and Bus Widths of DRAM Control Pins
Pin name
Data bus in 16-bit mode
Data bus in 8-bit
mode
Remarks
2CAS/1WE
mode
1CAS/2WE
mode
RAS0
Area 4 RAS
Area 4 RAS
Area 4 RAS
•
Correspondence
between "L" and "H"
and lower 1 bit (A0) of
address for data bus in
16-bit mode
•
"L":"0"
•
"H":"1"
CASL: CAS corresponding
to area containing
"0" in A0
CASH: CAS
corresponding
to area containing
"1" in A0
WEL: WE corresponding
to area containing
"0" in A0
WEH: WE corresponding
to area containing
"1" in A0
RAS1
Area 5 RAS
Area 5 RAS
Area 5 RAS
CS0L
Area 4 CASL
Area 4 CAS
Area 4 CAS
CS0H
Area 4
CASH
Area 4 WEL
Area 4 CAS
CS1L
Area 5 CASL
Area 5 CAS
Area 5 CAS
CS1H
Area 5
CASH
Area 5 WEL
Area 5 CAS
DW0X
Area 4 WE
Area 4 WEH
Area 4 WE
DW1X
Area 5 WE
Area 5 WEH
Area 5 WE
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 ...