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 _____________________________________________________ Chat with your friends as soon as they come online. Get Rediff Bol at http://bol.rediff.com |
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DPRAM Interfac with 56F805
Started by ●March 5, 2001
Reply by ●March 6, 20012001-03-06
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 MG> _____________________________________ MG> Note: If you do a simple "reply" with your email client, only the author of this message will receive your answer. MG> You need to do a "reply all" if you want your answer to be distributed to the MG> entire group. MG> _____________________________________ MG> About this discussion group: MG> To Join: MG> To Post: MG> To Leave: MG> Archives: http://www.egroups.com/group/motoroladsp MG> More Groups: http://www.dsprelated.com MG> ">http://docs.yahoo.com/info/terms/ |