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.