Serial data transmission including idle bits
First Claim
1. A method of communicating data between first means for processing configured for a control function and second means for processing configured for a slave function over a serial interface;
- wherein said interface comprises two lines only, a bi-directional data line and a uni-directional clock line;
said method comprising;
transmitting a clock signal from said first means for processing over said clock line to said second means for processing, and concurrently carrying out one of the two following functions;
(1) transmitting one of a control frame and data frame from said first means for processing over said serial interface to said second means for processing; and
(2) transmitting a data frame from said second means for processing over said serial interface to said first means for processing;
said method further comprising transmitting as part of each frame a control identification portion for identifying a frame as one of a control frame and a data frame, and transmitting following said control identification potion a plurality of data bits bounded by idle bits, both said first means for processing and said second means for processing freeing said bi-directional data line for a change in direction of data transmission during each said idle bit.
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Accused Products
Abstract
A serial data interface communicates data between a control processor (1) and one or more slave processors (2) via a serial bus (3). Typically the control processor (1) may be formed in a hand held or lap top computer and the slave processor (2) in a peripheral device for the computer. The control processor (1) transmits a clock signal over a clock line in the serial bus (3) to the slave processor (2). At the same time, control or data frames are transmitted from the control processor (1) the slave processor (2) or data frames are transmitted from the slave processor (3) to the control processor (1). Each data frame has a control portion which identifies the frame as a control frame or as a data frame, and following the control portion a plurality of data bits bounded by idle bits. Both the slave processor (2) and the control processor (1) free the data line for a change in the direction of data transmission during each idle bit.
In a preferred example, each control frame includes a select bit identifying the control frame as a slave select frame or as a slave control frame. Each slave control frame includes data transmission parameters which set the slave processor (2) to read or write one or more data frames subsequent to the current control frame.
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Citations
23 Claims
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1. A method of communicating data between first means for processing configured for a control function and second means for processing configured for a slave function over a serial interface;
- wherein said interface comprises two lines only, a bi-directional data line and a uni-directional clock line;
said method comprising;transmitting a clock signal from said first means for processing over said clock line to said second means for processing, and concurrently carrying out one of the two following functions;
(1) transmitting one of a control frame and data frame from said first means for processing over said serial interface to said second means for processing; and
(2) transmitting a data frame from said second means for processing over said serial interface to said first means for processing;said method further comprising transmitting as part of each frame a control identification portion for identifying a frame as one of a control frame and a data frame, and transmitting following said control identification potion a plurality of data bits bounded by idle bits, both said first means for processing and said second means for processing freeing said bi-directional data line for a change in direction of data transmission during each said idle bit. - View Dependent Claims (2, 3, 4, 5)
- wherein said interface comprises two lines only, a bi-directional data line and a uni-directional clock line;
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6. A system for communicating serial data comprising:
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first means for processing configured for a control function; second means for processing configured for a slave function; and serial interface means linking said first means for processing to said second means for processing, said serial interface means comprising a bi-directional data line and a uni-directional clock line only; said first means for processing including means for generating a clock signal for transmission over said clock line to said second means for processing and concurrently carrying out one of the two following functions;
(1) transmitting one of a control frame and a data frame from said first means for processing over said serial interface means to said second means for processing; and
(2) receiving a data frame transmitted over said serial interface means form said second means for processing;
said first means for processing including first means for transmitting control frames and data frames onto said serial interface means and first means for reading data frames from said serial interface means;and said second means for processing including second means for transmitting data frames onto said serial interface means, and second means for reading control frames and data frames from said serial interface means, and means for receiving said clock signal form said clock line and synchronizing said second means for transmitting and second means for reading with said first means for processing in response to said clock signal, wherein said first and second means for transmitting and said first and second means for reading include means for transmitting and reading respectively frames comprising a control identification portion identifying a frame as one of a control frame and a data frame, and following said control portion a plurality of data bits bounded by idle bits, both said first and second means for processing freeing said data line for a change in direction of data transmission during each idle bit. - View Dependent Claims (7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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21. A computing system comprising:
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a portable personal computer including first means for processing configured for a control function; a peripheral device including second means for processing configured for a slave function; and serial interface means linking said first means for processing to said second means for processing for communication of serial data therebetween, said serial interface means comprising a bi-directional data line and a uni-directional clock line only; generating a clock signal for transmission over said clock line to said second means for processing and concurrently carrying out one of the two following functions;
(1) transmitting one of a control frame and a data frame from said first means for processing over said serial interface means to said second means for processing; and
(2) receiving a data frame transmitted over said serial interface means from said second means for processing;
said first means for processing including first means for transmitting control frames and data frames onto said serial interface means and first means for reading data frames from said serial interface means;and said second means for processing including second means for transmitting data frames onto said serial interface means and second means for reading control frames and data frames from said serial interface means, wherein said first and second means for transmitting and said first and second means for reading include means for transmitting and reading respectively frames comprising a control portion identifying a frame as one of a control frame and a data frame, and following said control portion a plurality of data bits bounded by idle bits, both said first and second means for processing freeing said data line for a change in direction of data transmission during each idle bit, said second means for processing including means for receiving said clock signal from said clock line and synchronizing said second means for transmitting and second means for reading with said first means for processing in response to said clock signal. - View Dependent Claims (22, 23)
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Specification