Method and system for transmitting data from a unidirectional transmitter to a receiver
First Claim
1. A method for communicating data between a display device operating as a unidirectional transmitter and a receiver, comprising the steps of:
- at the display device,displaying a plurality of scanline at a selected baud rate for the transmitter, the scan lines defining a synchronization signal for receipt by the receiver; and
at the receiver,receiving the synchronization signal,measuring a synchronization parameter from the synchronization signal by determining a time differential between a first scan line and a second scan line of the synchronization signal, andselecting a baud rate for the receiver based on the synchronization parameter.
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Accused Products
Abstract
A method and apparatus for programming a device, such as a universal remote control unit, using a light source, such as a CRT computer monitor coupled to a conventional personal computer. A unidirectional flow of data from the transmitter is used to configure to the receiver. Specifically, a method is provided for synchronizing the baud rates and bytes-per-frame of the receiver and the transmitter. The receiver baud rate is selected based on a "55 hex" synchronization signal received from the transmitter. The receiver measures a synchronization parameter to determine the exact baud rate of the transmitter, to which the receiver synchronizes. Thus, transmitter-to-transmitter baud rate differences, such as those caused by design differences and manufacturing tolerances, do not limit the rate at which data may be transmitted from a particular transmitter to a particular receiver. A method is also provided for verifying the integrity of data received at the receiver. Data is transmitted in segments, and an integrity check parameter is included in each segment. The integrity check parameter includes a "check-sum" parameter that denotes the number of bytes of data in the segment and/or a packet number that indicates the number of the packet in a sequence of data packets defining a data segment. The receiver compares the number of bytes received in the segment to the number of bytes denoted by the integrity check parameter. If the number of bytes segment does not match the number of bytes denoted by the integrity check parameter, the receiver indicates an error condition.
48 Citations
25 Claims
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1. A method for communicating data between a display device operating as a unidirectional transmitter and a receiver, comprising the steps of:
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at the display device, displaying a plurality of scanline at a selected baud rate for the transmitter, the scan lines defining a synchronization signal for receipt by the receiver; and at the receiver, receiving the synchronization signal, measuring a synchronization parameter from the synchronization signal by determining a time differential between a first scan line and a second scan line of the synchronization signal, and selecting a baud rate for the receiver based on the synchronization parameter. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 24, 25)
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10. A display device operation as a unidirectional transmitter for transmitting data to a receiver, comprising:
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means for determining a maximum baud rate for the display device; means for selecting a baud rate for the display device equal to about the lesser of the maximum baud rate for a known receiver and the maximum baud rate for the display device; and means for displaying a synchronization signal at the selected baud rate for the display device, the synchronization signal comprising a synchronization parameter for receipt by a receiver configured to measure baud rate for the display device based on the synchronization parameter by determining a time differential between a first scan line and a second scan line of the synchronization signal and to set the baud rate of the receiver to match the baud rate of the display device. - View Dependent Claims (11, 12, 13)
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14. A receiver for receiving data from a display device operating as a unidirectional transmitter, comprising:
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means for receiving a synchronization signal from the display device; means for measuring a synchronization parameter from the synchronization signal by determining a time differential between a first scan line and a second scan line of the synchronization signal; and means for selecting a baud rate for the receiver based on the synchronization parameter. - View Dependent Claims (15, 16, 17)
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18. A computer-readable medium storing a program module comprising instructions which, when executed by a computer system comprising a processing unit, a memory storage device, and a user input/output system including a CRT, cause the computer system to perform the steps of:
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retrieving configuration parameters associated with the CRT from the memory storage device; computing the maximum baud rate at which the CRT may be operated as a unidirectional transmitter; selecting a baud rate for the CRT equal to about the lesser of the maximum baud rate for a known receiver and the maximum baud rate at which the CRT may be operated as a unidirectional transmitter; and displaying a synchronization signal on the CRT at the selected baud rate for operating the CRT, the synchronization signal comprising a synchronization parameter for receipt by a receiver configured to measure baud rate for the CRT based on the synchronization parameter by determining a time differential between a first scan line and a second scan line of the synchronization signal and to set the baud rate of the receiver to match the baud rate of the CRT. - View Dependent Claims (19)
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20. A computer-readable medium storing a program module comprising instructions which, when executed by a receiver comprising a processing unit, cause the receiver to perform the steps of:
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receiving a synchronization signal comprising alternating illuminated and non-illuminated horizontal scan lines on a CRT; measuring a synchronization parameter comprising the time between the display of two consecutive illuminated horizontal scan lines on the CRT; selecting a baud rate for the receiver based on the synchronization parameter; and indicating a lock condition upon selecting the baud rate for the receiver.
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21. In a receiver comprising a processing unit, a memory storage device, and a photo-detector, a method for receiving data displayed on a CRT, comprising the steps of:
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receiving a synchronization signal displayed on the CRT via the photo-detector, the synchronization signal comprising a plurality of bits wherein each bit comprises a line displayed on the CRT; measuring a synchronization parameter from the synchronization signal; selecting a baud rate for the receiver based on the synchronization parameter; indicating a lock condition upon selecting the baud rate for the receiver; receiving a data segment displayed on the CRT, the data segment comprising a plurality of bits wherein each bit comprises a line displayed on the CRT; receiving an integrity check parameter displayed on the CRT, the integrity check parameter comprising a plurality of bits wherein each bit comprises a line displayed on the CRT; determining whether the data segment was properly received based on the integrity check parameter; and if the data segment was not properly received, indicating an error condition.
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22. In a computer system comprising a processing unit, a memory storage device, and a user input/output system including a CRT, a method for transmitting data from the CRT, comprising the steps of:
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retrieving the number of scan lines per frame, and the vertical refresh rate, of the CRT from the memory storage device; computing the maximum baud rate at which the CRT may be operated as a unidirectional transmitter; selecting a baud rate for the CRT equal to about the lesser of the maximum baud rate for a known receiver and the maximum baud rate at which the CRT may be operated as a unidirectional transmitter; displaying a synchronization signal on the CRT at the selected baud rate for the CRT, the synchronization signal comprising a plurality of bits wherein each of a plurality of the consecutive horizontal scan lines displayed on the CRT comprises a bit of the synchronization signal, the synchronization signal comprising a synchronization parameter for receipt by a receiver configured to measure baud rate for the CRT based on the synchronization parameter and to set the baud rate of the receiver to match the baud rate of the CRT; displaying a data segment on the CRT, the data segment comprising a plurality of bits wherein each of a plurality of the consecutive horizontal scan lines displayed on the CRT comprises a bit of the data segment; and displaying an integrity check parameter on the CRT denoting an amount of data comprising the data segment, the integrity check parameter comprising a plurality of bits wherein each of a plurality of the consecutive horizontal scan lines displayed on the CRT comprises a bit of the integrity check parameter. - View Dependent Claims (23)
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Specification