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DPRAM Interfac with 56F805

Started by MOHAN G March 5, 2001
Hi there,

I have the following questions regarding the use of DSP56F805
processor, if some one can help me out.

I am doing digital design for control card using the DSP56F805. And I have
problem in interfacing DPRAM with the above processor.

The problem that I see with the use of a Dual Port Ram with the DSP is that
all varieties of DP Ram that I could find have period of 10ns after /WR is
asserted (i.e. goes low) in which the DPRam outputs are driving the data bus.

Unfortunately the DSP will also require to drive the bus, with
the data to be written, at some time overlapping with the DPRam and thus we have
a bus conflict.

What I need is a recommendation for a Dual Port Ram that can be used with
the DSP56F805 device.

Examples of the DPRam are Cypress CY7C024, Integrated Device Technology
IDT70V24 Thanks in advance,

Mohan

_____________________________________________________
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Hi Mohan,

I used the old model of the Motorola MCM69D536 Dual Port memory.

You can use the Motorola MCM69D618, it's better than the one I used,
has more memory space and less pins, that you don't need anyway.

This memories models runs up to 83 MHz, but I had used the same clock
frequency of the DSP processor. I tested w/ cristal frequencies
ranging from 16MHz, 20MHz, 40MHz and 70 MHz in a wire-wrap board and
it worked ...

... but, the DSP I had used was the 56811 and later the 56824. Both of
them worked properly with the DSP. I didn't try the 56F805 yet.

I also interfaced it with a ISA bus of an IBM-PC compatible. regards,

Silvio --------------------------

Silvio Szafir E-mail:

Mechatronics
University of Sao Paulo
EPUSP - PMR

Av. Prof. Mello Moraes, 2231 Fone: +55 (11) 3818-5575
Cidade Universitaria ext.225
Sao Paulo, SP - Brasil
05508-900 Fax: +55 (11) 3813-1886

--------------------------

Monday, March 05, 2001, 1:30:18 PM, you wrote:

MG> Hi there,

MG> I have the following questions regarding the use of DSP56F805
processor, if some one can help me out.

MG> I am doing digital design for control card using the DSP56F805. And I
have problem in interfacing DPRAM with
MG> the above processor.

MG> The problem that I see with the use of a Dual Port Ram with the DSP is
that all varieties of DP Ram that I could
MG> find have period of 10ns after /WR is asserted (i.e. goes low) in which the
MG> DPRam outputs are driving the data bus.

MG> Unfortunately the DSP will also require to drive the bus,
with the data to be written, at some time
MG> overlapping with the DPRam and thus we have a bus conflict.

MG> What I need is a recommendation for a Dual Port Ram that can be used
with the DSP56F805 device.

MG> Examples of the DPRam are Cypress CY7C024, Integrated Device Technology
IDT70V24 MG> Thanks in advance,

MG> Mohan

MG> _____________________________________________________
MG> Chat with your friends as soon as they come online. Get Rediff Bol at
MG> http://bol.rediff.com

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