2 Ring Oscillator Worker
2 : Ring Oscillator Worker
- Author: algofoogle (Anton Maurovic)
- Description: Simple digital logic, doing work, driven by a ring oscillator
- GitHub repository
- Open in 3D viewer
- Open in Tiny Tapeout Explorer
- Clock: 0 Hz
How it works
An internal simple digital counter block can be driven by an external clock or an internal ring oscillator, and then be fed data through external pins. It will run as fast as it can to try and produce a result, which can then be read back out.
How to test
- Set
clock_sel=1 (internal ring oscillator is used as the clock source). Ring-osc clock, divided by 16, should be present oncdebug-- expected to be on the order of 12.5MHz to 25MHz. - Set
mode=0 (we're going to load the number of cycles for which we want the worker to run). - Assert reset. No need to supply a clock on
clk. Expectdone==0. - Load a sequence of 4 bytes: a rising edge on
shiftloads each byte, in turn, viadin[7:0]. First 2 bytes are a starting value (MSB first). The next 2 bytes are a cycle count. Inmode==0this cycle count is used, while inmode==1it is repurposed as the addend for an adder experiment. - After the 4th byte has been loaded, the worker should start, and set
done==1when it finishes. - When done,
dout[7:0]should be presenting the first byte (MSB) of the output data; shift out 4 bytes in total viadout[7:0]by raisingshifteach time again (which in turn loads 4 more bytes, so it will start again). The first 2 bytes out are the 'starting value' incremented by the counter value (i.e. it should be the starting value, plus the internal counter value), and the last 2 bytes are the internal counter value (which started at 0).
External hardware
Nothing special. Probably just an oscilloscope to see how fast it actually yields a result.
IO
| # | Input | Output | Bidirectional |
|---|---|---|---|
| 0 | din[0] | dout[0] | shift |
| 1 | din[1] | dout[1] | clock_sel |
| 2 | din[2] | dout[2] | mode |
| 3 | din[3] | dout[3] | stop |
| 4 | din[4] | dout[4] | |
| 5 | din[5] | dout[5] | running |
| 6 | din[6] | dout[6] | done |
| 7 | din[7] | dout[7] | cdebug |