Help With ALE pin in proteus

Hi,

Tried to connect the RTC and the 8255 (on separate accounts) to 8051 and wrote the code in assembly and in c. The ale pin in proteus just doesn't seem to be working. I cant understand what I'm doing wrong, have debugged the code several times its definitely correct. Please help!

Thanks.

Nobody can help you unless you post your code and proteus file. Zip and post it. I have used Proteus 8051 ALE pin and it works fine.

Hi,

Thanks for the reply.

Have posted the zip file for rtc interfacing. It contains the asm file and the proteus design file.

Please let me know how it works.


Thanks.

Why you need ALE. 8051 sends device (RTC) address and then write or read command to device. Any port can be used. ALE of 8051 is used while using P0 which has AD0 to AD1. AD0 to AD1 can be used to send address and data which you are not using. You are using P2 which has only address lines but even that is not used in your project. You only need digital I/O pins to communicate. I haven't seen the datasheet of that RTC but it receives address and send data on the same ADx bus. Try using P0 to communicate with the device as it is made to send address and receive data. If you use P2 then you have to make P2 as output port while sending address and commands to RTC and then you have to make P2 as input to read in data from RTC and you can't do that.

Hi,

Thanks for the reply.

Actually I had connected it to Port 0 only. Uploaded the wrong file by mistake. It wasn't working when i had connected to port 0.

https://www.edaboard.com/threads/184795/
https://www.slideshare.net/aismahesh/8051-microprocessor

i have remade all the connections.. no luck with ale pin. isnt the ale pin supposed to toggle continuously? its not happening and no data is going through port0. please help.. that pdf had exactly only 2 lines written about ale pin