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PRELIMINARY
S3C6400X RISC MICROPROCESSOR
DRAM CONTROLLER
5-3
Preliminary product information describe products that are in development,
for which full characterization data and associated errata are not yet available.
Specifications and information herein are subject to change without notice.
SDRAM MEMORY INTERFACE
DRAM Controller supports up to two chips of same type and can assign a maximum of 256 MByte address space
per chip. All chips in the same port share all pins, except clock enable signals and chip select signals. An example
of DDR SDRAM memory interface connection is shown in figure 5-2. Mobile DDR SDRAM can be connected
similar to the DDR SDRAM. SDR SDRAM and mobile SDR SDRAM are connected similar to DDR SDRAM
,
except that DQS pins are not connected. External Memory Pin configuration is as shown in table 5-1 and 5-2.
Reset value of CKE is controlled by SPCONSLP[4]. If the value is zero, Xm0CKE and Xm1CKE are zero when
reset. If the value is one, Xm0CKE and Xm1CKE are one when reset.
Table 5-1 Memory Port 0 Pin Description
Signal
Type
Description
Xm0SCLK Input
Memory
clock
Xm0SCLKn
Input
Memory clock (negative)
Xm0CKE
Input
Clock enable per chip
Xm0CSn[6:7]
Input
Chip select per chip (active low)
Xm0RAS
Input
Row address strobe (active low)
Xm0CAS
Input
Column address strobe (active low)
Xm0WEndmc
Input
Write enable (active low)
Xm0ADDR[13:0] Input Address
bus
Xm0ADDR[15:14] Input Bank
select
Xm0DATA[15:0] Inout Data
bus
Xm0DQM[1:0]
Input
Data bus mask bits
Xm0DQS[1:0]
Inout
Data strobe inout, DDR and mDDR only
Table 5-2 Memory Port 1 Pin Description
Signal
Type
Description
Xm1SCLK Input
Memory
clock
Xm1SCLKn
Input
Memory clock (negative)
Xm1CKE[1:0]
Input
Clock enable per chip
Xm1CSN[1:0]
Input
Chip select per chip (active low)
Xm1RAS
Input
Row address strobe (active low)
Xm1CAS
Input
Column address strobe (active low)
Xm1WEN
Input
Write enable (active low)
Xm1ADDR[13:0] Input Address
bus
Xm1ADDR[15:14] Input Bank
select
Xm1DATA[31:0] Inout Data
bus
Xm1DQM[3:0]
Input
Data bus mask bits
Xm1DQS[3:0]
Inout
Data strobe inout, DDR and mDDR only