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Altera_Forum
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17 years ago

Help RAM

hi, i am quite new to vhdl and quartus ii. i have coded a 16x8 ram using vhdl in quartus , and y need a ram of 256kb , when y chage the address_width to 131072, that is the number of bits that...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
17 years ago

The calculation is clearly wrong. A 256 kByte RAM with a data with of 16 has 128 k words. This is equivalent to only 2^17 addresses, in other words an address width of 17

The reported Quartus out of memory error may result from trying to synthetisize an unavailable large RAM.

It may be meaningful to check first, if your present FPGA device has sufficient internal RAM. You would need at least an EP3C55 or larger Stratix device.