Note
This is a mirror of this repo/directory, so it can be found easier.
This PCB is compatible to the Pmod interface and can hold up to 6 PSRAM chips and one QSPI Flash chip.
| Pmod Pin | Function |
|---|---|
| 1 | D3 |
| 2 | CLK |
| 3 | D0 |
| 4 | CS A1 |
| 7 | D1 |
| 8 | D2 |
| 9 | CS A0 |
| 10 | CS A2 |
The select line of the chips is driven by a decoder (SN74AHC138). The selection works as follows:
| A2 | A1 | A0 | Selected Chip |
|---|---|---|---|
| 0 | 0 | 0 | Flash |
| 0 | 0 | 1 | RAM 0 |
| 0 | 1 | 0 | RAM 1 |
| 0 | 1 | 1 | RAM 2 |
| 1 | 0 | 0 | RAM 3 |
| 1 | 0 | 1 | RAM 4 |
| 1 | 1 | 0 | RAM 5 |
| 1 | 1 | 1 | RAM 6 |
You can check out the PCB in your browser using KiCanvas.