I have a development board with an EP4CE6E22C8 FPGA. And I have the following verilog code in Quartus Prime:
module Test(out);
output [7:0] out;
assign out = 8'b00111100;
endmodule
The pin planner has been configured as pointed by the schematic. The problem is that 0 turn on the LED and 1 turn off the LED. I think this is a strange behaviour since the typical one is 1=on and 0=off.
Anybody know if there is any option (in pin planner, quartus prime or whatever) to change this behaviour?
Thanks.
The behavior is a function of the board and how the LED was hooked to the PIN. Externally, a low is required to activate the LED.
You can change the behavior though through abstraction which is always useful.
module Test(out);
output [7:0] out;
wire [7:0] my_led;
// The application layer
assign my_led = 8'b11000011; // All inverted from the original
// The hardware abstraction layer
assign out = ~my_led; // Bitwise invert make the polarity as you desire.
endmodule