Encoder

Encoder

Also called: Priority Encoder.

Function

Selects the most significant one bit on the input and encodes this as a binary number on the output.

Notation

"BIN_OF_MSB" = binary value of input's most significant bit that has a value of one.

Comments

All zeros on the input of the encoder is an ambiguous condition since the output is the same as the input with a single bit in the least significant position. The "Valid" output can be used to flag this condition.

Parameters

Name	Description
WIDTH	Width of the Y and Q ports.

Tagged Values

Name	Variants
Registered	No, Yes
Valid	UnUsed, Used
Enable	UnUsed, Used

Inputs

Name	Width	Condition	Description
D	2**WIDTH	None	Input bits to be encoded.
Enable		Registered = No	if (Enable) Y = BIN_OF_MSB; else Y=0;
ClockEn		Registered = Yes	if (ClockEn) Q = BIN_OF_MSB

Outputs

Name	Width	Condition	Description
Y	WIDTH	Registered = No	BIN_OF_MSB
Q	WIDTH	Registered = Yes	BIN_OF_MSB
Valid		Valid = Used	if (D == 0) Valid = 0; else Valid = 1;