T89C51AC2 (CC01 or similar) with EXTRAM (6264)?

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Has anyone used T89C51AC2 with external RAM, I'm using it
and I have a latch for address, but it isn't working, like some bits
are written and some not...

Has anyone done this, are there any problems to be expected.

I use

int xram blablah[4096]

in Keil compiler, and I'm getting signals
out of processor, for reading about 200 ns RD, it should be
enough for RAM (read and write under 100 ns), but it doesn't work
as expected.

I dont have logic anaylzer so it will be tricky to find out what is
happening (unfortunately I dont even have storage oscilloscope),
so please do write your problems with processor to RAM interface?

Thanx



Re: T89C51AC2 (CC01 or similar) with EXTRAM (6264)?
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Might be worth looking at your latch circuit. The address I think is valid on
the negative transition of ALE, so maybe your latch is latching on the positive
edge and causing timing problems? Use a 74HC374 with inverter on clock input or
a 74HC373. Also beware of overloading the multiplexed address / data bus if you
have other devices hung on it apart from your RAM.  These are general 8051
comments and not particularly aimed at your variant.

Re: T89C51AC2 (CC01 or similar) with EXTRAM (6264)?


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   Use decoupling caps and also select diff mfrs of the 373 or 573 latch.
personally never had much luck with the Temic part.


Re: T89C51AC2 (CC01 or similar) with EXTRAM (6264)?
It was the connection problem, thanx on thought anyways.

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valid on
positive
input or
if you
8051



Re: T89C51AC2 (CC01 or similar) with EXTRAM (6264)?
Quoted text here. Click to load it
on
positive

That was the problem, my colegue connected ALE on /OE and LE to +5V on
PCB, and it should have been /OE to GND and LE to ALE.

Thanx on help...



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