
4 bit up/down binary counter with enable
direction | pin name     | function  
----------+--------------+-------------------
in        | clk          | clk
in        | rst_n        | rst_n
in        | ui_in[0]     | test      (test mode)
in        | ui_in[1]     | ud        (up/down)
in        | ui_in[2]     | en        (enable)
out       | ui_out[3:0]  | cnt[3:0]  (count)
Connect input pin EN to VDD
Connect input pin TEST to GND
Connect input pin UD to VDD or GND through a switch
Connect input pin RST_N to an R-C startup circuit
Connect input pin CLK to a 50 MHz square waveform
Connect the output pins CNT[3:0] to 4 LEDs
switch <br> 4 LEDs <br> R-C startup circuit
| # | Input | Output | Bidirectional | 
|---|---|---|---|
| 0 | test | cnt[0] | |
| 1 | ud | cnt[1] | |
| 2 | en | cnt[2] | |
| 3 | cnt[3] | ||
| 4 | |||
| 5 | |||
| 6 | |||
| 7 |