Small Hardware Description Language

SHDL | Board

Board Simulation

SHDL tool includes graphical simulation of some FPGA board peripheral components: buttons, LED, rotary encoder and various displays. Board support can be enabled on the Setup window and the board is then accessed by clicking on a Board button.

Connection of a circuit model with the board is through predefined port signal names:

• btn: in u4, four input buttons
• rot: in u2, rotary encoder input
• led: out u8, eight LEDs displayed on the board
• bcd: out u8, numeric 7-segment display, eaach decoded 4 bits of bcd

The code board1 uses described peripheral units. By click on Start, a simulation with interactive board graphics is performed.

entity board1
 btn: in u4;
 rot: in u2;
 led, bcd: out u8;
begin
 led <= rot & "00" & btn;
 if btn(0) then 
   bcd <= bcd + 1
 end
end