A QSPI Pmod board designed in KiCad with one SPI Flash and two PSRAMs.
| Pmod | TinyTapeout | Function | Note |
|---|---|---|---|
| PMOD1 | uio[0] | CS0 (Flash) | Cut trace to disable (see below) |
| PMOD2 | uio[1] | SD0/MOSI | |
| PMOD3 | uio[2] | SD1/MISO | |
| PMOD4 | uio[3] | SCK | Short CK ("CLOCK cap") pin pair for delay by 22pF cap |
| PMOD5 | uio[4] | SD2 | |
| PMOD6 | uio[5] | SD3 | |
| PMOD7 | uio[6] | CS1 (RAM A) | Cut trace to disable (see below) |
| PMOD8 | uio[7] | CS2 (RAM B) | Cut trace to disable (see below) |
Note
On the bottom side of the PCB, you can cut the traces for any of the 3 CS pins to disable its respective memory IC. When cut, a 1k resistor pulls up the chip's /CS to disable it. In this case, the respective pin could be used (via header thru-hole on the other side of the cut) as either an input or output.