Key identifying circuit, key identifying method and STB (Set Top Box)

Abstract

The invention belongs to the field of single chip control and provides a key identifying circuit, a key identifying method and an STB (Set Top Box). The key identifying circuit comprises N ports, at least N diodes and at least N and at most N*(N-1) keys, wherein N*N intersection points are formed by the lines of the N ports and N row lines vertical to the lines; at least one diode is placed at the intersection points in each row; at most one key is placed at a free intersection point without the diode, and one end of the key is connected with the line of the key while the other end is connected with the row line of the key; and a control end of the key is supplied to a user for selecting and controlling. In the key identifying circuit provided by the invention, diodes are used for separating keys and less ports are used for identifying more keys, so that the single chip with less resource is selected, the cost of the single chip is lowered, the size of the corresponding PCB (Printed Circuit Board) is reduced and the cost of the whole device is saved.

Description

technical field [0001] The invention belongs to the field of single-chip microcomputer control, and in particular relates to a key recognition circuit, a key recognition method and a set-top box. Background technique [0002] Button recognition technology is widely used in the recognition function of the button on the set-top box panel. When the single-chip microcomputer detects that a button on the set-top box panel is pressed, it will send a signal to control the set-top box to perform corresponding operations. Existing button identification technology mainly uses IO port to scan the matrix of rows and columns, and uses only one intersection point between each row and each column to determine which button is pressed. When there are six buttons to be identified, 5 IO ports are needed; when there are nine buttons to be identified, six IO ports are needed; in this way, the IO ports are relatively used too much, because the current single-chip microcomputer with more IO ports ...

AI Technical Summary

Problems solved by technology

[0003] The purpose of the embodiments of the present invention is to provide a key recognition circuit, aiming to solve the problem of high cost caused by excessive use of IO ports in the prior art

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