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Altera_Forum's avatar
Altera_Forum
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17 years ago

Simultaneous Write/Read to on chip dual port RAM

Obviously simultaneous writes will cause problems. In our case, one Avalon Master is reading while the other Master is writing. So, the question is, will simultaneous write and read of t...
Altera_Forum's avatar
Altera_Forum
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17 years ago

vjAlter,

From the Altera link "It will always set the altsyncram's parameter READ_DURING_WRITE_MODE_MIXED_PORTS to "DONT_CARE" which will result in unknown outputs when reading from the same memory location that is being written to by the other port." This parameter can be NEW_DATA, OLD_DATA, or DONT CARE

I interpreted "Unknown outputs" as garbage values.

You're saying that DONT CARE effectively means you don't care if you get NEW or OLD DATA. I'm guessing that the actual result (new vs. old) will then be part/optimizer/compiler specific. And yes, it doesn't matter whether I get new or old data.

That does eliminate some fears about changing SOPC Builder and accidentally losing the setting.

Thanks