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Memory

A single 16 bit DDR2 memory device is used. The design supports 128MB or 256MB of memory. The standard configuration is 256MB at 400MHz.

The design uses a single MT47H128M16RT-25E:C 400MHZ memory from Micron which comes in an 84-Ball 9.0mm x 12.5mm FBGA package. The addressing configuration is shown in the following table:

Parameter 128 Meg x 16
Configuration 16 Meg x 16 x 8 banks
Refresh Count 8K
Row Address A[13:0] (16K)
Bank Address BA[2:0] (8)
Column Address A[9:0] (1K)

The DDR2 connects direct to the processor and no external interface devices are required. Power is supplied to the DDR2 via the 1.8V rail on the TPS65217B.