Forum Discussion

Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
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
Icon for Honored Contributor rankHonored Contributor
17 years ago

It requires extra circuitry to provide the "old data" option. So there are two reasons for giving the option:

1 - The "old data" option is not available for M-RAM blocks (available in Stratix series). So if you select the "old data" option and have chosen "Auto" as the RAM type, you are restricting the synthesis tool as to what types of RAM blocks it can use. You are taking away some flexibility from the compiler as it can no longer use M-RAM.

2 - Under certain circumstances you can get a performance decrease when using the "old data" option. For most designs, this data path will not be the limiting factor.

Jake