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Altera_Forum's avatar
Altera_Forum
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13 years ago

ROM contents confusion

Hai, I have vhdl code for store a constant in ROM. The ROM is divided into odd and even; ROMO and ROME as shown below: library IEEE; use IEEE.STD_LOGIC_1164.all; -- use ieee.STD_LOGI...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
13 years ago

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Ignorant question: why do you think to need to split the ROM in odd and even at all? For hardware processors, odd and even are used when e.g. two 8-bit ROMs are connected to a 16-bit databus. This won't be necessary in FPGA where you can define a 16-bit ROM directly.

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Hai FvM,

Actually I get the code in open source and I don't know why the ROM is splits to odd and even. That is the exact question that I try to ask. I build the ROM table refer to the code, but I don't understand how they manage the input address with the constant value.

However, how to build the ROM table if I have eight constant values that will be multiply with eight input data? Is it not necessary if I split the constant to two ROM table (4 constant each ROM)?.. Thanks in advance