SED1335/RA8835 memory read problem

ferblaha · Joined: 24 Dec 2007 Posts: 3

Hello, I´m new in the forum. I´m having problems with the memory read of the SED1335. After I send the MREAD command, and I try to execute the "receive byte" procedure, I never get to really read the memory byte. I always read the same value that I last wrote to the data port.

Does anyone know what could be the problem?
Thank you all, and merry xmas.
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Fernando Blaha
BG ELECTRONICA

PCM programmer · Joined: 06 Sep 2003 Posts: 21708

What is your compiler version ?
There was a bug in the SED1335.c file in some versions.
It affects the setCursorAddress() function. That function is used
to set the address which is used by the MREAD command.
This post shows the correct code:
http://www.ccsinfo.com/forum/viewtopic.php?t=32684&start=25

In vs. 4.064, CCS has the correct code for that routine in SED1335.c.
They fixed it in some earlier version, but I don't know the exact one.

ferblaha · Joined: 24 Dec 2007 Posts: 3

Hello, I have version 3.6.0.98 of the compiler. This version only included the SED1335 library but compatible with 8080 bus mode, and I need it for the 6800 mode.

So, I wrote my own library, using some of the functions "compatible" in both modes. I´m looking right now at the other post you linked me, so I´ll see if there is something that can help me there.

Thank you, and I´ll tell you if there is some news!

Fernando
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Fernando Blaha
BG ELECTRONICA

ferblaha · Joined: 24 Dec 2007 Posts: 3

No, that´s not the problem. It seems like the data pins of the SED never get to be output, like if they are always in the input state...
_________________
Fernando Blaha
BG ELECTRONICA