公开(公告)号：JPH0643989A

公开(公告)日：1994-02-18

申请号：JP19012291

申请日：1991-07-30

Applicant: ADVANCED MICRO DEVICES INC

Inventor： DEIRU II GARITSUKU ,  ARAN EFU HENDORITSUKUSON

IPC: G06F3/023 ,  H03M11/20 ,  H04M1/26

Abstract: PURPOSE: To effectively use an input terminal pin by detecting the state of a key pad switch with the set of monitor input terminals, which correspond to a selected mode. CONSTITUTION: When a system operates in a first operation mode, row input terminal pins 60-68 are connected to row conductors 160-168. Column input terminal pins 70-78 are connected to row conductors 170-178. In such a case the key pad monitor of a telephone set 12 can support the key pad 26 having 25 key pad switches. At a second operation mode, the row input terminal pins 60-64 are connected to the row conductors 160-164 and the column input terminal pins 70-74 are connected to the row conductors 170-174. In such a case, nine key pad switches are supported. The remaining pins are used for a purpose except for the monitoring of the key pad 26.