Hardware interface and protocol for a mobile radio transceiver

Claims

What is claimed is:

1. In a digital mobile radio transceiver including radio frequency circuit means for transmitting and receiving radio frequency signals, and a digital signal processor connected to control said radio frequency circuit means, a method of communicating signals between a peripheral device and said digital signal processor over a serial data bus having first and second data lines and a service request line, said method comprising the steps of:

(1) seizing control of said service request line with said peripheral device;

(2) receiving, with said peripheral device, a poll message passed over said first data line in response to seizure of said service request line;

(3) applying, with said peripheral device, a preset identification code to said second data line in response to receipt of said poll message;

(4) receiving, with said peripheral device a further poll message passed over said first data line in response to application of said identification code to said second line, said further poll message including said preset identification code;

(5) applying, with said peripheral device, a data and/or command message to said second data line in response to receipt of said further poll message; and

(6) releasing said service request line.

2. A method as in claim 1 wherein said applying step (5) includes applying the following in sequence to said second data line:

(a) a 3-bit message type value which specifies a type of message;

(b) a 5-bit unit identification code;

(c) a data type value specifying a data type;

(d) a data byte number value specifying a number of data bytes to follow, the sum of the number of bits in said data byte number value and the number of bits in said data type value being equal to eight;

(e) plural data bytes, the quantity of said data bytes being equal to the number specified by said data byte number value; and

(f) an error-checking value.

3. A method as in claim 2 wherein said data byte number value is five bits in length.

4. A method as in claim 2 wherein said data byte number value is six bits in length.

5. In a digital mobile radio transceiver including radio frequency circuit means for transmitting and receiving radio frequencies, and a digital signal processor connected to control said radio frequency circuit means, a method of communicating between peripheral units and said digital signal processor over a serial data bus having first and second data lines and a service request line, said method comprising the steps of:

(1) detecting seizure of said service request line by a peripheral unit with said digital signal processor;

(2) applying, with said digital signal processor, a poll message to said first data line in response to said detected seizure;

(3) receiving, with said digital signal processor, a preset identification code passed by said peripheral unit over said second data line in response to said applied poll message;

(4) applying, with said digital signal processor, a further poll message including said preset identification code to said first data line in response to receipt of said preset identification code; and

(5) receiving, with said digital signal processor, a further message applied to said second data line responsive to said further poll message.

6. A method of communicating digital data signals between a control head including a first switch having only two alternate positions and a second switch having at least three alternate positions, and a digital mobile radio frequency receiver adapted for connection to said control head via a serial data bus, said method including:

(1) sensing a change in position of said first switch and sensing the absolute position of said first switch;

(2) sensing a change in position of said second switch and sensing the direction of such position change; and

(3) generating a switch position message if said sensing steps (1) and (2) reveal a change in position of either of said first and second switches, said message including:

(a) a plural bit value identifying which of said first and second switches has changed position, and

(b) a single bit value which indicates (b1) the absolute position of said first switch if said sensing step (1) reveals first switch has changed position, and (b2) the direction of the positional change of said second switch of said sensing step (2) reveals said second switch has changed position.

7. A method of communicating digital data signals between (1) a control head including a longitudinal array of discrete single character alpha-numeric displays 1, . . . ,x,x+1, . . . ,N, and (2) a digital mobile radio frequency transceiver adaptable for connection to said control head via a serial data bus, said method including:

(1) receiving an insert character message including the following:

an insert character command,

a value x specifying one of said discrete displays in said array, and

M values each indicating the character to be displayed, M being an integer greater than 1;

(2) scrolling the characters displayed by said displays M positions in a preset direction along said array beginning at the display specified by said value x such that the character formerly displayed by display x is displayed by display x+N;

(z3) displaying the first of said M values with the display specified by said value x; and

(4) displaying the rest of said M values in displays x+1, . . . ,x+M-1.

8. A method of communicating digital data signals between (1) a control head including a loudspeaker and an alarm indicator, and (2) a digital mobile radio frequency transceiver adapted for connection to said control head via a serial data bus, said method including:

receiving a serial audio control command having a message byte including a most significant bit which specifies on/off status and at least one lower order bit specifying one of said loudspeaker and said alarm indicator; and

controlling the one of said loudspeaker and said alarm indicator specified by said lower order bit in accordance with the on/off status specified by said most significant bit.

9. A digital mobile radio transceiver including:

radio frequency circuit means for transmitting and receiving radio frequency signals;

a digital signal processor means connected to control said radio frequency circuit means;

a serial data bus having first and second data lines and a service request line, said bus connected to said processor means;

means connected to said bus for seizing control of said service request line;

means connected to said bus for receiving a poll message passed over said first data line in response to seizure of said service request line;

first applying means connected to said bus for applying a preset identification code to said second data line in response to receipt of said poll message;

means connected to said bus for receiving a further poll message passed over said first data line in response to application of said preset identification code to said second line, said further poll message including said preset identification code;

second applying means connected to said bus for applying a data and/or command message to said second data line in response to receipt of said further poll message; and

means connected to said bus for releasing said service request line.

10. A transceiver as in claim 9 wherein said second applying means includes means for applying the following in sequence to said second data line:

(a) a 3-bit message type value which specifies a type of message;

(b) a 5-bit unit identification code;

(c) a data type value specifying a data type;

(d) a data byte number value specifying a number of data bytes to follow, the sum of the number of bits in said data byte number value and the number of bits in said data type value being equal to eight;

(e) said number of data bytes, the quantity of said data bytes being equal to the number specified by said data byte number value; and

(f) an error-checking value.

11. A transceiver as in claim 10 wherein said data byte number value is five bits in length.

12. A transceiver as in claim 10 wherein said data byte number value is six bits in length.

13. A digital mobile radio transceiver including:

radio frequency circuit means for transmitting and receiving radio frequencies;

a digital signal processor connected to control said radio frequency circuit means;

a serial data bus, having first and second data lines and a service request line, connected to said digital signal processor wherein said digital signal processor includes:

means connected to said data bus for detecting seizure of said service request line by a peripheral unit also connected to said serial data bus;

means connected to said data bus for applying a poll message to said first data line in response to said detected seizure;

means connected to said data bus for receiving a preset identification code passed by said peripheral unit over said second data line in response to said applied poll message;

means connected to said data bus for applying a further poll message including said preset i