Radio receiver system including a control unit and a remote unit
First Claim
1. A communication system comprising a control unit including a master computer and a remote unit including a slave computer, a single wire bidirectional data bus interconnecting said master and slave computers, output means coupled to said slave computer, input means coupled to said master computer for selecting operating functions of said output means, said master computer communicating information to said slave computer regarding the status of said input means and receiving information from said slave computer regarding the status of said output means, said master computer controlling the timing of the transfer of said information by periodically initiating a bit transfer period and assuming control of the data bus during a first portion of said period and relinquishing control of the data bus during the remaining portion of said period, said slave computer responsive to the initiation of said bit transfer period for reading the data bus during said first portion and thereafter assuming control of the data bus, said master computer reading the data bus during said remaining portion, said slave computer relinquishing control of the data bus prior to initiation of a succeeding bit transfer period, whereby a bit is transmitted from the master to the slave computer and a bit is transmitted from the slave to the master computer during each bit transfer period.
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Abstract
An automobile radio receiver system includes a control unit located in the passenger compartment and a remote unit, for example, in the trunk compartment of the automobile. The control unit includes a master microcomputer which controls a display and responds to keyboard inputs. The remote unit includes the radio receiver which is controlled by a slave microcomputer. The master and slave microcomputers are interconnected by a single wire data bus. Data regarding keyboard inputs are transmitted to the slave and data regarding receiver status is transmitted to the master. The data is interleaved on a bit by bit basis with master controlling the timing of data transmission thereby permitting a relatively imprecise timing base in the slave.
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Citations
10 Claims
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1. A communication system comprising a control unit including a master computer and a remote unit including a slave computer, a single wire bidirectional data bus interconnecting said master and slave computers, output means coupled to said slave computer, input means coupled to said master computer for selecting operating functions of said output means, said master computer communicating information to said slave computer regarding the status of said input means and receiving information from said slave computer regarding the status of said output means, said master computer controlling the timing of the transfer of said information by periodically initiating a bit transfer period and assuming control of the data bus during a first portion of said period and relinquishing control of the data bus during the remaining portion of said period, said slave computer responsive to the initiation of said bit transfer period for reading the data bus during said first portion and thereafter assuming control of the data bus, said master computer reading the data bus during said remaining portion, said slave computer relinquishing control of the data bus prior to initiation of a succeeding bit transfer period, whereby a bit is transmitted from the master to the slave computer and a bit is transmitted from the slave to the master computer during each bit transfer period.
- 2. A radio receiver system comprising a control unit including a master computer and a remote unit including a slave computer, a single wire bidirectional data bus interconnecting said master and slave computers, radio receiver means coupled to said slave computer and controlled thereby, input switch means coupled to said master computer for selecting operating functions of said radio receiver means, said master computer including memory means for storing data regarding the status of said radio receiver, display means controlled by said master computer for indicating the status of said radio receiver means in accordance with the data in said memory means, means normally applying power to said master computer means for continuously energizing said memory means, for selectively applying power to said slave computer, said master computer communicating data to said slave computer regarding the status of said input switch means and receiving data from said slave computer regarding the status of said radio receiver means for updating said memory means and said display means, said master computer controlling the timing of the transfer of said data by periodically initiating a bit transfer period during which a bit of data is transmitted from the master computer to the slave computer and a bit of data is transmitted from the slave computer to the master computer.
- 5. A radio receiver system comprising a control unit including a master computer and a remote unit including a slave computer, a single wire bidirectional data bus interconnecting said master and slave computers, radio receiver means coupled to said slave computer and controlled thereby, input switch means coupled to said master computer for selecting operating functions of said radio receiver means, said master computer including memory means for storing data regarding the status of said radio receiver, display means controlled by said master computer for indicating the status of said radio receiver in accordance with the data in said memory, means normally applying power to said master computer means for continuously energizing said memory means, means for selectively applying power to said slave computer, said master computer communicating data to said slave computer regarding the status of said input switch means and receiving data from said slave computer regarding the status of said radio receiver means for updating said memory means and said display means, each data word transferred between said master computer and said slave computer containing a plurality of bits, the bits of the words transferred from the master computer to the slave computer being interleaved with the bits transferred from the slave computer to the master computer.
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10. A radio receiver system comprising a control unit including a master computer and a remote unit including a slave computer, a single wire bidirectional data bus interconnecting said master and slave computers, radio receiver means coupled to said slave computer and controlled thereby, input switch means coupled to said master computer for selecting operating functions of said radio receiver means, said master computer including memory means for storing data regarding the status of said radio receiver, display means controlled by said master computer for indicating the status of said radio receiver in accordance with the data in said memory means, means normally applying power to said master computer means for continuously energizing said memory means, power switch means located at said master control unit for selectively applying power to said slave computer, a pull up means located at said remote unit connected between said data bus and said power switch means to thereby place said bus in a first predefined state when power is applied and a second predefined state when power is disconnected.
Specification