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Altera_Forum
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13 years ago

STD_LOGIC_VECTOR multipication

I keep getting an error using the '*' to multiply SLV's: use IEEE.numeric.std.all; constant COEFF : STD_LOGIC_VECTOR (5 downto 0) := x"3F"; signal EXPx63_LTCHD : S...
Altera_Forum's avatar
Altera_Forum
Icon for Honored Contributor rankHonored Contributor
13 years ago

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EXPx63_LTCHD <= std_logic_vector(unsigned(EXP_LTCHD) * unsigned(COEFF));

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Yes this solves the first problem involved with the code.

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Pay attention to x"3F" that might be considered as a negative number.

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There's no reason to expect this. But x"3F" is 8 bit length where 6 bits are needed.

"111111" is the intended 6-Bit value.

Third problem, the product bit length must be increased by one.