Cbira: Pagină nouă: The numerator is a sequential circuit that uses a register to generate a sequence of numbers. The simplest numerator generates a sequence of ascending consecutive numbers. The size...

2018-04-11T23:55:14Z

Pagină nouă: The numerator is a sequential circuit that uses a register to generate a sequence of numbers. The simplest numerator generates a sequence of ascending consecutive numbers. The size...

Pagină nouă

The numerator is a sequential circuit that uses a register to generate a sequence of numbers. The simplest numerator generates a sequence of ascending consecutive numbers. The size of the counter is given by the number of bits of the registers used.

The schematic of this device is as follows:

[[File: numarator.png | Block schematic of a counter]]

'''Note:''' The count can be used as a frequency divider because each bit has a period twice as high as the previous one, and the bit 0 has a double period over the clock signal:

{| class="wikitable"
|- bgcolor="#dddddd" align="center"
|Value ||   0 ||   1 ||   2 ||   3 ||   4 ||   5 ||   6 ||   7 ||   8 ||   9 || 10 || 11 || 12 || 13 || 14 || 15 || Waveforms
|- bgcolor="#aa9999" align="center"
|Bit 0 || bgcolor="#ddeeff" | 0 || 1 || bgcolor="#ddeeff" | 0 || 1 || bgcolor="#ddeeff" | 0 || 1 || bgcolor="#ddeeff" | 0 || 1 || bgcolor="#ddeeff" | 0 || 1 || bgcolor="#ddeeff" | 0 || 1 || bgcolor="#ddeeff" | 0 || 1 || bgcolor="#ddeeff" | 0 || 1 || [[File: num0.png]]
|- bgcolor="#aa9999" align="center"
|Bit 1 || bgcolor="#ddeeff" | 0 || bgcolor="#ddeeff" | 0 || 1 || 1 || bgcolor="#ddeeff" | 0 || bgcolor="#ddeeff" | 0 || 1 || 1 || bgcolor="#ddeeff" | 0 || bgcolor="#ddeeff" | 0 || 1 || 1 || bgcolor="#ddeeff" | 0 || bgcolor="#ddeeff" | 0 || 1 || 1 || [[File: num1.png]]
|- bgcolor="#aa9999" align="center"
|Bit 2 || bgcolor="#ddeeff" | 0 || bgcolor="#ddeeff" | 0 || bgcolor="#ddeeff" | 0 || bgcolor="#ddeeff" | 0 || 1 || 1 || 1 || 1 || bgcolor="#ddeeff" | 0 || bgcolor="#ddeeff" | 0 || bgcolor="#ddeeff" | 0 || bgcolor="#ddeeff" | 0 || 1 || 1 || 1 || 1 || [[File: num2.png]]
|- bgcolor="#aa9999" align="center"
|Bit 3 || bgcolor="#ddeeff" | 0 || bgcolor="#ddeeff" | 0 || bgcolor="#ddeeff" | 0 || bgcolor="#ddeeff" | 0 || bgcolor="#ddeeff" | 0 || bgcolor="#ddeeff" | 0 || bgcolor="#ddeeff" | 0 || bgcolor="#ddeeff" | 0 || 1 || 1 || 1 || 1 || 1 || 1 || 1 || 1 || [[File: num3.png]]
|}

== Interface of a counter ==

The interface of a numerator necessarily contains the following ports:
* Clock signal port;
* output signal port, which is even the counting register.

In addition, there may still be:
* Reset port;
* port that controls the counting direction;
* port that stops or starts counting;
* port giving the maximum value the numerator can reach;
* port that commands to load a start value in the counter of the counter and the port on which this value is given;
* etc.

== Implementing a counter ==

As a sequential circuit, a counter is implemented exclusively with [[Verilog #Blocks always sequential. Non-blocking assignments | always sequential blocks]].

The Counter - Revizia istoricului

Cbira: Pagină nouă: The numerator is a sequential circuit that uses a register to generate a sequence of numbers. The simplest numerator generates a sequence of ascending consecutive numbers. The size...