Matrix-type keyboard scanning circuit and scanning and encoding method

• Main Authors: LING YUN, CHEN GANG, KONG LINGSHUANG, ZENG HONGBING, XIAO SHENPING, NIE HUI
• Format: Patent
• Language: Chinese; English
• Published: 15.06.2016
• Subjects: BASIC ELECTRONIC CIRCUITRY; CODE CONVERSION IN GENERAL; CODING; DECODING; ELECTRICITY

The invention relates to a matrix-type keyboard scanning circuit which consists of a matrix-type keyboard, a first shifting register, a second shifting register, a state code register and an encoder. A scanning and encoding method of the scanning circuit comprises the steps of: by control of a scanning pulse and a shifting pulse which meet the specific time sequence requirement, converting single key operations and combined key operations of the matrix-type keyboard or kept states into effective state codes and invalid state codes, which have the same binary length; and outputting an effective key number corresponding to each effective state code or outputting an invalid key number corresponding to all the invalid state codes after encoding by the encoder. Different single key operations, combined key operations or kept states are only shown on the aspect of difference of the state codes; and if key operation functions need to be increased or decreased or need to be adjusted, only the encoder needs to be chan