Sdram Ddr Component Connections; Ddr Sdram Layout Considerations - Freescale Semiconductor MCF5329 Reference Manual

SDRAM Controller (SDRAMC)
18.3.3

SDRAM DDR Component Connections

Figure 18-3 shows a block diagram using 16-bit wide DDR SDRAM (such as Micron MT46V8M16) and
flash (such as Spansion AM29DBB160G).
SDRAM Controller
SD_CLK
SD_CLK
SD_CKE
SD_CS0
SD_RAS
SD_CAS
SDWE
SD_A10
SD_DQS[3:2]
BE/BWE/DQM[3:2]
SD_A[23:0]
SD_D[31:16]
D[15:0]
R/W
OE
FB_CS0
DRAMSEL
18.3.4

DDR SDRAM Layout Considerations

Due to the critical timing for DDR SDRAM, a number of considerations should be taken into account
during PCB layout:
• Minimize overall trace lengths.
18-12
GND
Figure 18-3. Example 2.5V, 16-bit DDR SDRAM System
MCF5329 Reference Manual, Rev 3
2.5V DDR SDRAM
CLK
CLK
CKE
CS
RAS
CAS
WE
A10/AP
DQS[1:0]
DQM[3:2]
A[15:14]
BA[1:0]
A[13:11,9:0]
A[13:11,9:0]
D[15:0]
1.25V
VREF
2.5V Flash
A[23:1]
A[22:0]
D[15:0]
WE
OE
CE
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