706 Multi-Precision Multiplier
706 : Multi-Precision Multiplier
- Author: Felix Trask
- Description: Variable-precision 2/4/8-bit multiplier with selectable mode control
- GitHub repository
- Open in 3D viewer
- Open in Tiny Tapeout Explorer
- Clock: 0 Hz
How it works
Architecture Overview:
This block is a variable-precision unsigned multiplier. It operates in three precision modes determined by external control pins:
- 2-bit mode (
mode = 00): Direct load -> 4-bit product - 4-bit mode (
mode = 01): Direct load -> 8-bit product - 8-bit mode (
mode = 10): Two-cycle sequential load -> 16-bit product (two-cycle sequential load)
Pin Mapping:
All 8 bidirectional pins are set as inputs (uio_oe = 8'b0000_0000x)
| Signal Name | Pin Assignment | Direction | Description |
|---|---|---|---|
data_in[7:0] |
ui_in[7:0] |
Input | Main 8-bit operand data input |
mode[1:0] |
uio_in[1:0] |
Input | Mode selection between 2-bit, 4-bit, and 8-bit |
load_en |
uio_in[2] |
Input | Cycle control for 8-bit mode |
reserved |
uio_in[7:3] |
Input | Unused inputs |
product_out[7:0] |
uo_out[7:0] |
Output | Product data output |
Operand Loading:
2-bit mode:
- Input: Single cycle
- data_in[1:0] = Operand A
- data_in[3:2] = Operand B
- Output: Single cycle
- product_out[3:0] = A * B
- product_out[7:4] = zero-padded (
4'b0000)
4-bit mode:
- Input: Single cycle
- data_in[3:0] = Operand A
- data_in[7:4] = Operand B
- Output: Single cycle
- product_out[7:0] = A * B
8-bit mode:
- Input: Double cycle
- Cycle 1: (
load_en = 0)- data_in[7:0] = Operand A
- Cycle 2: (
load_en = 1)- data_in[7:0] = Operand B
- Cycle 1: (
- Output: Double cycle
- Cycle 1: (
load_en = 0)- product_out[7:0] = lower bytes of A * B (
product[7:0])
- product_out[7:0] = lower bytes of A * B (
- Cycle 2: (
load_en = 1)- product_out[7:0] = higher bytes of A * B (
product[15:8])
- product_out[7:0] = higher bytes of A * B (
- Cycle 1: (
How to test
Run the automated Cocotb testbench using make:
cd test
make
## External hardware
N/A
IO
| # | Input | Output | Bidirectional |
|---|---|---|---|
| 0 | data_in[0] | product_out[0] | mode[0] |
| 1 | data_in[1] | product_out[1] | mode[1] |
| 2 | data_in[2] | product_out[2] | load_en |
| 3 | data_in[3] | product_out[3] | |
| 4 | data_in[4] | product_out[4] | |
| 5 | data_in[5] | product_out[5] | |
| 6 | data_in[6] | product_out[6] | |
| 7 | data_in[7] | product_out[7] |