That suggests I should use an always block sensitive to all of the inputs. The output digit should keep its value until changed so it is a reg type.Īnd any time an input changes we want the display to update. And it has a 7-bit output ( seg) representing which segments to enable.

So what would sseg_display look like? Well it takes a 4-bit input ( hex) value representing a hexadecimal digit. That seems reasonable enough and very similar to what we’ve seen before. an is active low, turn on an, others off

The code for the top-level module looks like the following. Then we can go ahead and create the top-level module sseg_top and flesh it out. Let’s assume that I will call that module sseg_display. Designing the seven-segment display driver codeįor now let’s assume that we create a module that can take a 4-bit input connected to the slide switches, and generate a 7-bit output connected to the seven-segment display. So the digit would be represented as 7’b1000000 which calls for all segments on except for the middle center one which is seg. The seg bits map to the individual segments starting from the center top and moving clockwise around the digit. So we set a seg signal to 1 to turn it off and 0 to turn it on. In future projects we will use the an signals to enable/disable individual digits. For this project I will simply set an to 0 at the start for the single digit that I will use. The an signal is active low, so it is set to 0 to enable it. Note that the an signal represents the anode, or ground, for all seven LEDs on the first seven-segment digit. Trying to do so could damage the hardware! The Artix-7 output pins can’t drive all four digits simultaneously. Trying to do so could damage the hardware! So we will have to come up with a plan for how to deal with this later.Īn important thing to understand is that the signals for the individual segments on all four digits connect together. The Artix-7 output pins can’t drive all for digits at the same time. An important thing to understand is that the signals for the individual segments on all four digits connect together. And so we just need to come up with a way to map from a 4-bit number to the 7-bit LED segment outputs seg. Set_property CFGBVS VCCO įor the most part you treat the seven-segment display like a set of LEDs.

# Configuration options, can be used for all designs Set_property IOSTANDARD LVCMOS33 Ĭreate_clock -add -name sys_clk_pin -period 10.00 -waveform ] # - rename the used ports (in each line, after get_ports) according to the top level signal names in the project # - uncomment the lines corresponding to used pins

7 segment hex code