s3c2800 Samsung Semiconductor, Inc., s3c2800 Datasheet - Page 15

• Manufacturer Part Number: s3c2800
• Description: 32-bit Risc Microprocessor
• Manufacturer: Samsung Semiconductor, Inc.

PRELIMINARY DATA SHEET
SIGNAL DESCRIPTIONS
BUS CONTROLLER
OM[1:0]
ADDR[24:0]
DATA[31:0]
nSCS[3:0]
nWE
nWBE[3:0]
nBE[3:0]
nWAIT
nOE
ENDIAN
DRAM/SDRAM
nDRAS[3:0]
nDCAS[3:0]
nSDRAS
nSDCAS
nSDCS[3:0]
DQM[3:0]
SDCLK
SDCKE
INTERRUPT CONTROL UNIT
EXTINT[7:0]
DMA
nXDREQ[1:0]
nXDACK[1:0]
Signal
I/O
IO
O
O
O
O
O
O
O
O
O
O
O
O
O
O
O
I
I
I
I
I
OM [1:0] is used to determines the bus width of static memory bank0 (boot ROM).
The pull-up/down resistor determines the logic level.
00 = 8-bit
ADDR [24:0] (Address Bus) outputs the memory address of the corresponding bank.
DATA [31:0] (Data Bus) inputs data during memory read and outputs data during
memory write. The bus width is programmable among 8/16/32-bit.
nSCS[3:0] (Static memory bank Select) are activated when the address of a static
memory is within the address region of each bank. The number of access cycles and
the bank size can be programmed.
nWE (Write Enable) indicates that the current bus cycle is a write cycle.
Write Byte Enable.
16-bit SRAM Byte Enable.
Request to prolong a current bus cycle. As long as nWAIT is Low, the current bus
cycle can’t be completed.
nOE (Output Enable) indicates that the current bus cycle is a read cycle.
It determines whether or not the data type is Little-endian or Big-endian. The pull-
up/down resistor determines the logic level during the reset cycle.
ENDIAN value is latched only at the rising edge of nRESET: when nRESET is Low,
the ENDIAN (GPC3) pin operates in input mode; nRESET becomes High, the
ENDIAN pin will automatically switch to output mode.
0 = Little-endian
Row Address Strobe.
Column Address Strobe.
SDRAM Row Address Strobe.
SDRAM Column Address Strobe.
SDRAM Chip Select.
SDRAM Data Mask.
SDRAM Clock (SDCLK = HCLK).
SDRAM Clock Enable.
External Interrupt request.
External DMA request.
External DMA acknowledge.
Table 3. S3C2800 Signal Descriptions
01 = 16-bit
10 = 32-bit
Description
1 = Big-endian
11 = Not used
S3C2800 MICROCONTROLLER
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