Browse Prior Art Database

RADIO Link Controller

IP.com Disclosure Number: IPCOM000061594D
Original Publication Date: 1986-Aug-01
Included in the Prior Art Database: 2005-Mar-09
Document File: 4 page(s) / 34K

Publishing Venue

IBM

Related People

Belyeu, SM: AUTHOR [+3]

Abstract

This article describes a radio link controller which implements a serial bidirectional communications protocol so that a host computer can be used to control an AM-FM radio. The radio link controller disclosed herein implements a full duplex 1K baud serial link protocol. It enables a personal computer (PC) to use a set of send/receive buffers to communicate with a remote AM-FM radio and to control various performance parameters. A block diagram of the controller is shown in Fig. 1. The send/receive buffers and the timer are part of an adapter that is an interface between the PC and the link controller. The primary elements of the radio link controller are the idle controller, the command executor, and the timer interrupt handler.

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RADIO Link Controller

This article describes a radio link controller which implements a serial bidirectional communications protocol so that a host computer can be used to control an AM-FM radio. The radio link controller disclosed herein implements a full duplex 1K baud serial link protocol. It enables a personal computer (PC) to use a set of send/receive buffers to communicate with a remote AM-FM radio and to control various performance parameters. A block diagram of the controller is shown in Fig. 1. The send/receive buffers and the timer are part of an adapter that is an interface between the PC and the link controller. The primary elements of the radio link controller are the idle controller, the command executor, and the timer interrupt handler. After the radio is turned ON, it is the responsibility of the idle controller to maintain communications. If messages are not continuously sent to the radio, the AM-FM receiver will sense the inactivity and turn the radio OFF. The idle controller avoids this premature termination by sending "no operations" commands to the radio when no action messages are in the send buffer. The continuous communication allows the radio to cycle through its current state even when the computer has no commands for the radio. These state messages describe parameters such as the current volume and equalizer settings. The idle controller recognizes these messages and sends them to the receive buffer. They are stored in non-volatile memory so that they can be used when the radio is turned OFF and then back ON. The idle controller is also responsible for initializing the interrupt handler and for transferring the appropriate action messages to the command executor. The command executor executes the commands sent by the PC to the radio. The executor evaluates the command and uses the flag registers and the counter array to initialized the sequence controller. The following is a summary of the operations performed by the command executor: OE

Determine if the radio is currently ON or OFF. If it is ON, the executor prohibits the use of the START commands. Only parameter modification commands are allowed. If the radio is OFF, an initialization sequence is transmitted before any action commands are executed. This sequence involves sending a start bit and one data bit until the radio responds with a Memory Dump Request message. OE Execute the Warm and Cold Start commands. When the command executor receives the Memory Dump Request message from the radio, it must generate the appropriate response. If a Cold Start message was sent from the PC the command executor will respond with a "no operation" message. The radio will turn ON and use the default state parameters that are stored in its internal memory. For a Warm Start, the command executor will set the appropriate flags and counters so that the timer interrupt handler and sequence controller will transmit a sequence of new state parameters to the radio. OE Determ...