I'm trying to work with the meant display. When I use the pins P2.0-7 as GPIO (as well, as RW and E signals), I can control the display pretty well, but it's very slow and demands a lot of extra code to write. So I'm trying to use EMC to make the process faster and clearer. The following problems occured:
1. The line RW is constantly 1, so I cannot write anything.
Ok, let's drop the line to the ground - firstly I just want to write smth to the display.
2. Cannot see proper E signal generated by EMC. Instead, I can see multiple (circa 4 - 10) impulses generated each time I make step in Debug mode on _any_ command, not only those about the LCD. This results in output like "AAAAAAA" instead of "A" in Debug mode and no output at all when i leave the programme to run by itself.
What am I doing wrong?
Hi,
You should check the timing of the LCD screen, especially on the Enable signal. You could also take a look to the following documents:
http://www.nxp.com/docs/en/application-note/AN10771.pdf
http://www.nxp.com/docs/en/application-note/AN10950.pdf
https://community.nxp.com/thread/341823
https://community.nxp.com/message/764854
https://community.nxp.com/docs/DOC-106148
Hope this will be useful for you.
Best regards!
/Carlos
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The problem solved. In 8-bit mode I can not see RW signal to set 0 for writing. Having configured EMC for 16-bit mode I archieved the data to be written. My opinion is that something is wrong with the processor. I have excluded any software or curcuit development mistakes.