943 Stopwatch with 7-seg Display
943 : Stopwatch with 7-seg Display
- Author: Manoranjan
- Description: A simple stopwatch with minutes and seconds display on 7-seg, implemented for TinyTapeout.
- GitHub repository
- Open in 3D viewer
- Clock: 50000000 Hz
How it works
The design is a digital stopwatch that counts seconds and minutes using the global Tiny Tapeout clock (~12 MHz). A clock divider generates a 1 Hz enable pulse, which increments the seconds counter. When seconds reach 59, they reset to 0 and minutes increment. Both values (minutes and seconds) are converted into BCD format and driven onto a 4-digit multiplexed 7-segment display.
Control is provided through input pins: ui_in[0] → Start stopwatch ui_in[1] → Stop stopwatch
The output pins (uo_out and uio_out) are connected to the 7-segment display’s segment and digit-select lines.
How to test
Apply reset (rst_n = 0 for a few clock cycles, then rst_n = 1). Drive ena = 1 (project enable). Set ui_in[0] = 1 to start counting; clear it afterwards. Observe seconds and minutes incrementing on the display. Set ui_in[1] = 1 to stop counting. Outputs can also be monitored in simulation by watching: uo_out[6:0] → segment bits uo_out[7] → decimal point uio_out[3:0] → active digit select
External hardware
To see the stopwatch visually, connect: uo_out[6:0] → segment lines (a–g) of a common-anode 7-segment display uo_out[7] → decimal point (optional) uio_out[3:0] → digit enable lines (an0–an3)
IO
| # | Input | Output | Bidirectional |
|---|---|---|---|
| 0 | start | seg[0] | an[0] |
| 1 | stop | seg[1] | an[1] |
| 2 | seg[2] | an[2] | |
| 3 | seg[3] | an[3] | |
| 4 | seg[4] | ||
| 5 | seg[5] | ||
| 6 | seg[6] | ||
| 7 | dp |