There are two functional blocks - a ring oscillator with multiple taps, and a glitchless clock switch.
To test the oscillator - Input 0 is input to first inverter in the oscillator. One of the inverted outputs either 0 (slowest), 1 (mid), or 2 (fastest) should be connected to input 0. To test the clock switch - input 1 selects between clock0 (on input 2) and clock 1 (on input 3). Selected CLK appears on OUT3
# | Input | Output | Bidirectional |
---|---|---|---|
0 | 0 Osc In | 0 OSC OutSlow/segment a | none |
1 | 1 ClkSel | 1 OSC OutMid/segment b | none |
2 | 2 CLK0 in | 2 OSC OutFast/segment c | none |
3 | 3 Clk1 in | 3 ClkOut/segment d | none |
4 | none | segment e | none |
5 | none | segment f | none |
6 | none | segment g | none |
7 | none | dot | none |