Appearance
Behaviour
The lookup table component works much like the ROM component, but without a CS input and with a much more compact look.
The lookup table consists of an internal read-only memory whose data cell bit with is determined by the property "Data Bit Width". The size of the memory (i.e. the number of cells) is determined by the property "Address Bit Width".
Just like with a ROM component, double-click the symbol and edit the memory values of the lookup table.
During simulation, whenever the value at the address input "A" changes, the lookup table value addressed by "A" gets looked up and presented at the data output "D".
Pins
- A
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Address Input. Its bit width is determined by property "Address Bit Width". If any of its bits is undefined (high impedance), the effective address is determined by the value of the user preference "Undefined gate input behaviour", e.g. "Read as 0" or "Read as random".
- D
-
Data Output. Its bit width is determined by property "Data Bit Width".
Properties
- Address Bit Width
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Determines the number of lookup table entries.
- Data Bit Width
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Determines the number of bits of the lookup table entries.