This is an analog crossbar array used as a placeholder for future ReRAM projects. Poly Resistors are used instead of ReRAM between Met1 and Met2. Thus, this project has a fixed weight matrix. This project performs 4x4 matrix multiplication in one run.
6 analog pins and 8-bit digital input bus are used. First 4 analog pins (i.e. ua[3:0]) are used as inputs to the crossbar. The ua[4] is the supply voltage 0-1.8V (default: keep at 1.8V). The ua[5] is the output analog pin used for observing the output current (summing junction). First 4 digital input pins (i.e. ui_in[3:0]) control the 4 4-bit muxes on the input side. The ui_in[4:7] is used to control the column selection.
This project will need external off-the-shelf DACs and ADCs including a TIA or ADC that can convert output current into a readable voltage.
| # | Input | Output | Bidirectional |
|---|---|---|---|
| 0 | bit control 1 | ||
| 1 | bit control 2 | ||
| 2 | bit control 3 | ||
| 3 | bit control 4 | ||
| 4 | write/select control 1 | ||
| 5 | write/select control 2 | ||
| 6 | write/select control 3 | ||
| 7 | write/select control 4 |
ua | analog | Description |
|---|---|---|
| 0 | 11 | bit 1 |
| 1 | 6 | bit 2 |
| 2 | 10 | bit 3 |
| 3 | 7 | bit 4 |
| 4 | 9 | write 1 |
| 5 | 8 | select 1 |