| 摘要 |
A portable telephone apparatus for communication with a base station through a radio telephone channel. A microprocessor controller controls operation of the apparatus in accordance with an operational program. A connector is used for connecting the apparatus to a fixedly wired telephone line through a modem. A digital signal processor processes voice signals. The operational program is partially stored in an Electrically Erasable Programmable Read Only Memory (EEPROM). A first Random Access Memory (RAM) temporarily stores control signals to be used for amending the operational program stored in the EEPROM. A second RAM stores a portion of the operational program which is used for controlling operation of the digital signal processor. A switch which is responsive to the controller, selectively connects the second RAM to either the controller or the digital signal processor. The second RAM is connected to the digital signal processor during a normal operational mode and to the controller in a change mode wherein the second RAM's content is changed. A battery backup supplies battery power to the second RAM. The operational program is amended in response to control signals obtained through the connector. The control signals are transmitted over the fixedly wired telephone line and received through connector. |
