The Decoder - Revizia istoricului

Cbira la 10 mai 2018 07:00

2018-05-10T07:00:24Z

Cbira: /* Implementation */

2018-05-10T06:59:55Z

Implementation

Cbira: /* Interface */

2018-05-10T06:59:25Z

Interface

Cbira la 10 mai 2018 06:59

2018-05-10T06:59:11Z

Cbira la 10 mai 2018 06:58

2018-05-10T06:58:37Z

Cbira: Pagină nouă: The decoder is a combinational circuit which is used to identify the specified input value by setting the output of the bit on the corresponding index to the input. The decoder is...

2018-05-10T06:57:49Z

Pagină nouă: The decoder is a combinational circuit which is used to identify the specified input value by setting the output of the bit on the corresponding index to the input. The decoder is...

Pagină nouă

The decoder is a combinational circuit which is used to identify the specified input value by setting the output of the bit on the corresponding index to the input. The decoder is equivalent to a 1-bit multiplexer and the constant data input of 1.

For example, for a 4-bit decoder, the port table is shown below (the _ character can be used in Verilog to separate bits or numbers belonging to a base in writing a constant, for ease of reading; 16'b0100_0011_0100_0111)

{| class = "wikitable"
| - bgcolor = "# ddeeff" align = "center"
| '' 'INTRARE' '' || '' 'EXIT' ''
| - bgcolor = "# ddffdd" align = "center"
| 0000 || 0000_0000_0000_0001
| - bgcolor = "# ddffdd" align = "center"
| 0001 || 0000_0000_0000_0010
| - bgcolor = "# ddffdd" align = "center"
| 0010 || 0000_0000_0000_0100
| - bgcolor = "# ddffdd" align = "center"
| 0011 || 0000_0000_0000_1000
| - bgcolor = "# ddffdd" align = "center"
| 0100 || 0000_0000_0001_0000
| - bgcolor = "# ddffdd" align = "center"
| 0101 || 0000_0000_0010_0000
| - bgcolor = "# ddffdd" align = "center"
| 0110 || 0000_0000_0100_0000
| - bgcolor = "# ddffdd" align = "center"
| 0111 || 0000_0000_1000_0000
| - bgcolor = "# ddffdd" align = "center"
| 1000 || 0000_0001_0000_0000
| - bgcolor = "# ddffdd" align = "center"
| 1001 || 0000_0010_0000_0000
| - bgcolor = "# ddffdd" align = "center"
| 1010 || 0000_0100_0000_0000
| - bgcolor = "# ddffdd" align = "center"
| 1011 || 0000_1000_0000_0000
| - bgcolor = "# ddffdd" align = "center"
| 1100 || 0001_0000_0000_0000
| - bgcolor = "# ddffdd" align = "center"
| 1101 || 0010_0000_0000_0000
| - bgcolor = "# ddffdd" align = "center"
| 1110 || 0100_0000_0000_0000
| - bgcolor = "# ddffdd" align = "center"
| 1111 || 1000_0000_0000_0000
|}

== Interface ==

The interface of a decoder is made up of two signals:
* input of '' n '' bits;
* output of 2 <sup> n </ sup> bits.

== Implementation ==

There are several possible implementations for the decoder:
* using blocks '''generated for''';
* using blocks '''always''' combinational and '''case''';
* using a block '''assign''' and the left shift operator.

Although the last variant is not optimal from the point of view of the synthesized circuit, we will use this method because of the ease and short dimension of the description.

@@ Linia 5: / Linia 5: @@
 {| class = "wikitable"
 |- bgcolor = "#ddeeff" align = "center"
-|'''INTRARE''' || '''EXIT'''
+|'''INPUT''' || '''OUTPUT'''
 |- bgcolor = "#ddffdd" align = "center"
 |0000 || 0000_0000_0000_0001

@@ Linia 4: / Linia 4: @@
 {| class = "wikitable"
-|- bgcolor = "# ddeeff" align = "center"
+|- bgcolor = "#ddeeff" align = "center"
 |'''INTRARE''' || '''EXIT'''
-|- bgcolor = "# ddffdd" align = "center"
+|- bgcolor = "#ddffdd" align = "center"
 |0000 || 0000_0000_0000_0001
-|- bgcolor = "# ddffdd" align = "center"
+|- bgcolor = "#ddffdd" align = "center"
 |0001 || 0000_0000_0000_0010
-|- bgcolor = "# ddffdd" align = "center"
+|- bgcolor = "#ddffdd" align = "center"
 |0010 || 0000_0000_0000_0100
-|- bgcolor = "# ddffdd" align = "center"
+|- bgcolor = "#ddffdd" align = "center"
 |0011 || 0000_0000_0000_1000
-|- bgcolor = "# ddffdd" align = "center"
+|- bgcolor = "#ddffdd" align = "center"
 |0100 || 0000_0000_0001_0000
-|- bgcolor = "# ddffdd" align = "center"
+|- bgcolor = "#ddffdd" align = "center"
 |0101 || 0000_0000_0010_0000
-|- bgcolor = "# ddffdd" align = "center"
+|- bgcolor = "#ddffdd" align = "center"
 |0110 || 0000_0000_0100_0000
-|- bgcolor = "# ddffdd" align = "center"
+|- bgcolor = "#ddffdd" align = "center"
 |0111 || 0000_0000_1000_0000
-|- bgcolor = "# ddffdd" align = "center"
+|- bgcolor = "#ddffdd" align = "center"
 |1000 || 0000_0001_0000_0000
-|- bgcolor = "# ddffdd" align = "center"
+|- bgcolor = "#ddffdd" align = "center"
 |1001 || 0000_0010_0000_0000
-|- bgcolor = "# ddffdd" align = "center"
+|- bgcolor = "#ddffdd" align = "center"
 |1010 || 0000_0100_0000_0000
-|- bgcolor = "# ddffdd" align = "center"
+|- bgcolor = "#ddffdd" align = "center"
 |1011 || 0000_1000_0000_0000
-|- bgcolor = "# ddffdd" align = "center"
+|- bgcolor = "#ddffdd" align = "center"
 |1100 || 0001_0000_0000_0000
-|- bgcolor = "# ddffdd" align = "center"
+|- bgcolor = "#ddffdd" align = "center"
 |1101 || 0010_0000_0000_0000
-|- bgcolor = "# ddffdd" align = "center"
+|- bgcolor = "#ddffdd" align = "center"
 |1110 || 0100_0000_0000_0000
-|- bgcolor = "# ddffdd" align = "center"
+|- bgcolor = "#ddffdd" align = "center"
 |1111 || 1000_0000_0000_0000
 |}

@@ Linia 49: / Linia 49: @@
 There are several possible implementations for the decoder:
-* using blocks '''generated for''';
+* using blocks '''generate for''';
 * using blocks '''always''' combinational and '''case''';
 * using a block '''assign''' and the left shift operator.
 Although the last variant is not optimal from the point of view of the synthesized circuit, we will use this method because of the ease and short dimension of the description.

@@ Linia 44: / Linia 44: @@
 The interface of a decoder is made up of two signals:
 * input of '' n '' bits;
-* output of 2 <sup> n </ sup> bits.
+* output of 2 <sup> n </sup> bits.
 == Implementation ==