How to turn off the 4 digits of 7segment display

On the evaluation board of fpga spartan 3 has 4-digits 7segment display. The displays are usually used to display data or a limited character.

However, for applications that do not require this display, is needed to turn off all digits of 7segment display.  An example is a demo of the application in the post here, the appearance of the 4 digits 7segment can interfere with performance, so need to be turned off.

You need to know the workings of the 7segment 4digits display on the evaluation board of fpga spartan 3, please click here to know it. To turn off all digits of 7segment display is by disabling all common anode of 7segment display. To disable each digit is by setting the common anoda to logic 1, because each digit will active at logic 0.

Common anode pins of 7segment display is called as AN3, AN2, AN1, AN0 with a pin number in sequence are E13, F14, G14, D14.

There are two methods  are behavioral or schematic to turn off all the digits of the 7segment display.

Behavioral

Well I will refer vhdl code posted here. The trick is to add output port for each digit of AN3, AN2, AN1 and AN0 written in Entities Block. To be concise to use array of std_logic.

 

Finally, in Block of process use the initialization as “1111″. Here are excerpts vhdl code then there is the addition, the results become:

 

Finally, in Block of process use the initialization as “1111″. Here are excerpts vhdl code then there is the addition, the results become:

 

Schematic

If you are working on schematic design, you can use schematic editor to disable all 7segment display. Each common anode of 7segment digit must be pulled up to VCC using I/O marker, it’s mean give a logic 1. Next, gave a name each I/O marker, for example as AN0, AN1, AN2 and AN3. 

The following video will describe it:

 

DEMO

YouTube Preview Image

Last updated by at .

Avatar of Bambang Siswoyo

About Bambang Siswoyo

I am a college lecturer since 1988 at UB (University of Brawijaya) in the electronics department. My experience: Applications of Microprocessor system, Applications of Control System, Applications of Field Programmable Gate Array, Computer Programming in computer instrumentations. My hobby: Music especially playing the saxophone, hiking and exploring the countryside.
This entry was posted in Electronics, fpga and tagged , . Bookmark the permalink.

Leave a Reply

Your email address will not be published. Required fields are marked *

CAPTCHA Image

*

You may use these HTML tags and attributes: <a href="" title="" rel=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>