S3C2500B
PRODUCT OVERVIEW
1-15
Table 1-1. S3C2500B Signal Descriptions (Continue)
Group
Pin Name
Pin
Type
Pad Type
Description
Memory
Interface
(80)
ADDR[23:0]
ADDR[10]/AP
24
O
Phot20
Address bus.
The 24-bit address bus covers the full 16 M
word address range of each ROM/SRAM
/FLASH and external I/O bank.
In the SDRAM interface, ADDR[14:13] is
always used as bank address of SDRAM
devices. If SDRAM devices with 2 internal
bank is used, ADDR[13] should be connected
to the BA of SDRAM. If SDRAM devices with
4 internal bank is used, ADDR[14:13] should
be connected to the BA[1:0] of SDRAM.
ADDR[10]/AP is the auto precharge control
pin. The auto precharge command is issued at
the same time as burst read or burst write by
asserting high on ADDR[10]/AP.
XDATA[31:0]
32
I/O
phbsut20
External bi-directional 32bit data bus.
The S3C2500B supports 8 bit, 16bit, 32bit bus
with ROM/SRAM/Flash/Ext IO bank, but
supports 16 bit or 32 bit bus with SDRAM
bank.
nSDCS[1:0]
2
O
phot20
Not chip select strobe for SDRAM.
Two SDRAM banks are supported.
nSDRAS
1
O
phot20
Not row address strobe for SDRAM.
NSDRAS signal is used for both SDRAM
banks.
nSDCAS
1
O
phot20
Not column address strobe for SDRAM.
NSDCAS signal is used for both SDRAM
banks.
CKE
1
O
phob12
Clock Enable for SDRAM
CKE is clock enable signal for SDRAM.
nSDWE/nWE16
1
O
phot20
Not Write Enable for SDRAM or 16 bit
ROM/SRAM.
This signal is always used as write enable of
SDRAM and is used as write enable of only
16-bit ROM/SRAM/Flash.
(That is, It is not enabled for 8 bit Memory)
Summary of Contents for S3C2500B
Page 2: ...S3C2500B 32 BIT RISC MICROPROCESSOR USER S MANUAL Revision 1 ...
Page 17: ......
Page 25: ......
Page 80: ...PRODUCT OVERVIEW S3C2500B 1 46 NOTES ...
Page 296: ...MEMORY CONTROLLER S3C2500B 5 60 NOTES ...
Page 531: ...GDMA CONTROLLER S3C2500B 12 24 NOTES ...
Page 593: ...I O PORTS S3C2500B 15 12 NOTES ...