1bit Hi-Z IN/OUT single direction I/O

< Function description >

File name
Example code of uni-direction signal with high impedance control.
Signal description
This code shown uni-direction signal control example.
A uni-direction line is declared as ‘HiZIO_pin’.
A ‘IN_from_HiZIO’ siglal is declared as input signal.

At ‘OEN’ is ‘H’, a value of ‘OUT_to_HiZIO’ is transfered to ‘HiZIO_pin’.
Also, ‘OEN’ signal is ‘L’, ‘HiZIO_pin’ signal will be ‘Hi-Z’ status.

TruthTable :

  | OEN | OUT_to_HiZIO |
  |  L  |      HiZ     |
  |  H  | OUT_to_HiZIO |

By the way, a ‘IN_from_HiZIO’ signal always reflects ‘HiZIO_pin’ value.
This signal value is not effected by ‘OEN’ signal.

Even if designer wants to need an output direction signal, it **SHOULD** declare ‘High-Impedance’ pin with ‘**INOUT**’ property.
The NSL synthesis tool does not generate ‘High-Impedance’ pin with ‘output’ property.