Method for generating a clock signal for use in a data receiver, clock generator, data receiver and remote controlled access system for vehicles
First Claim
1. A method for generating a clock signal for use in a data receiver, the clock signal being substantially synchronised with data received by the data receiver, the received data comprising a sync word having a predetermined data frequency and predetermined value and being Manchester coded so that each bit of the sync word comprises a logic `1` in one phase of a clock period and a logic `0` in an anti-phase of the clock period, the method comprising the steps of:
- generating n clocks, each of the n clocks having a frequency which is substantially the predetermined data frequency and being out of phase with an adjacent clock of the n clocks by 1/n of the clock period, each of the n clocks further having one other clock of the n clocks in anti-phase therewith, wherein the data receiver comprises register means comprising n registers, each of the n registers being clocked by a respective one of the n clocks, and having an anti-phase register clocked by an anti-phase clock;
shifting the received data into each register of the n registers in parallel according to the respective clock of the n clocks;
comparing the contents of each register with a Manchester coded comparison word having the predetermined value and providing a comparison signal for each of the n registers, the comparison signal having a first logic state when the contents of the register match the comparison word and a second logic state when the contents of the register do not match the comparison word;
checking whether the contents of each register is inverted compared to the contents of its anti-phase register;
providing an output signal for each register, the output signal having a first logic state when the comparison signal for the register has a first logic state and the contents of the register is inverted compared to the contents of its anti-phase register, and a second logic state when the comparison signal of the register has a second logic state and/or the contents of the register is not inverted compared to the contents of its anti-phase register;
selecting one of the n clocks which clocks a register whose output signal has the first logic state; and
providing the selected one of the n clocks at an output, the selected one of the n clocks providing the clock signal.
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Accused Products
Abstract
A data receiver is arranged to receive data comprising a sync word having a predetermined data frequency (ftx) and predetermined value. A clock signal (SCLK) is generated which is substantially synchronised with the received data. The n clocks (CLK1-CLK8) are generated, each of the n clocks having a frequency (fclk) which is substantially the predetermined data frequency (ftx) and is out of phase with an adjacent clock of the n clocks by 1/n of a clock period. The sync word is sampled using each of the n clocks to determine which one of the n clocks is optimally synchronised with the sync word and to provide the determined one of the n clocks at an output (18). The determined one of the n clocks provides the clock signal (SCLK).
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Citations
15 Claims
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1. A method for generating a clock signal for use in a data receiver, the clock signal being substantially synchronised with data received by the data receiver, the received data comprising a sync word having a predetermined data frequency and predetermined value and being Manchester coded so that each bit of the sync word comprises a logic `1` in one phase of a clock period and a logic `0` in an anti-phase of the clock period, the method comprising the steps of:
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generating n clocks, each of the n clocks having a frequency which is substantially the predetermined data frequency and being out of phase with an adjacent clock of the n clocks by 1/n of the clock period, each of the n clocks further having one other clock of the n clocks in anti-phase therewith, wherein the data receiver comprises register means comprising n registers, each of the n registers being clocked by a respective one of the n clocks, and having an anti-phase register clocked by an anti-phase clock; shifting the received data into each register of the n registers in parallel according to the respective clock of the n clocks; comparing the contents of each register with a Manchester coded comparison word having the predetermined value and providing a comparison signal for each of the n registers, the comparison signal having a first logic state when the contents of the register match the comparison word and a second logic state when the contents of the register do not match the comparison word; checking whether the contents of each register is inverted compared to the contents of its anti-phase register; providing an output signal for each register, the output signal having a first logic state when the comparison signal for the register has a first logic state and the contents of the register is inverted compared to the contents of its anti-phase register, and a second logic state when the comparison signal of the register has a second logic state and/or the contents of the register is not inverted compared to the contents of its anti-phase register; selecting one of the n clocks which clocks a register whose output signal has the first logic state; and providing the selected one of the n clocks at an output, the selected one of the n clocks providing the clock signal. - View Dependent Claims (2, 3, 4, 5)
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6. A clock generator for generating a clock signal for use in a data receiver, the clock signal being substantially synchronised with data received by the data receiver, the received data comprising a sync word having a predetermined data frequency and a predetermined value, and being Manchester coded so that each bit of the sync word comprises a logic `1` in one phase of a clock period and a logic `0` in an anti-phase of the clock period, the clock generator comprising:
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means for generating n clocks, each of the n clocks having a frequency which is substantially the predetermined data frequency and being out of phase with an adjacent clock of the n clocks by 1/n of the clock period, each of the n clocks further having one other clock of the n clocks in anti-phase therewith; register means coupled to receive the received data, the register means comprising; n registers, each of the n registers being clocked by a respective one of the n clocks such that the received data is shifted into each register of the n registers in parallel according to the respective clock of the n clocks, each of the n registers having an anti-phase register clocked by an anti-phase clock, n decode logic coupled to respective registers of the n registers, each decode logic for comparing the contents of the respective register with a Manchester coded comparison word having the predetermined value and providing a comparison signal at an output, the comparison signal having a first logic state when the contents of the respective register match the comparison word and a second logic state when the contents of the respective register do not match the comparison word, and n logic gates for respective registers of the n registers, each logic gate being coupled to the decode logic of the respective register and to the decode logic of its anti-phase register for checking whether the contents of the respective register is inverted compared to the contents of its anti-phase register and for providing an output signal for the respective register, the output signal having a first logic state when the comparison signal for the register has a first logic state and the contents of the register is inverted compared to the contents of its anti-phase register, and a second logic state when the comparison signal of the register has a second logic state and/or the contents of the register is not inverted compared to the contents of its anti-phase register; and logic means for selecting one of the n clocks which clocks a register whose output signal has the first logic state and for providing the selected one of the n clocks as the clock signal for use in the data receiver. - View Dependent Claims (7, 8, 9, 10)
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11. A data receiver for receiving data transmitted by a data transmitter, the data receiver comprising a clock generator for generating a clock signal for use in a data receiver, the clock signal being substantially synchronised with data received by the data receiver, the received data comprising a sync word having a predetermined data frequency and a predetermined value, and being Manchester coded so that each bit of the sync word comprises a logic `1` in one phase of a clock period and a logic `0` in an anti-phase of the clock period, the clock generator comprising:
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means for generating n clocks, each of the n clocks having a frequency which is substantially the predetermined data frequency and being out of phase with an adjacent clock of the n clocks by 1/n of the clock period, each of the n clocks further having one other clock of the n clocks in anti-phase therewith; register means coupled to receive the received data, the register means comprising; n registers, each of the n registers being clocked by a respective one of the n clocks such that the received data is shifted into each register of the n registers in parallel according to the respective clock of the n clocks, each of the n registers having an anti-phase register clocked by an anti-phase clock, n decode logic coupled to respective registers of the n registers, each decode logic for comparing the contents of the respective register with a Manchester coded comparison word having the predetermined value and providing a comparison signal at an output, the comparison signal having a first logic state when the contents of the respective register match the comparison word and a second logic state when the contents of the respective register do not match the comparison word, and n logic gates for respective registers of the n registers, each logic gate being coupled to the decode logic of the respective register and to the decode logic of its anti-phase register for checking whether the contents of the respective register is inverted compared to the contents of its anti-phase register and for providing an output signal for the respective register, the output signal having a first logic state when the comparison signal for the register has a first logic state and the contents of the register is inverted compared to the contents of its anti-phase register, and a second logic state when the comparison signal of the register has a second logic state and/or the contents of the register is not inverted compared to the contents of its anti-phase register; and logic means for selecting one of the n clocks which clocks a register whose output signal has the first logic state and for providing the selected one of the n clocks as the clock signal for use in the data receiver. - View Dependent Claims (12)
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13. A remote controlled access system for vehicles comprising a data transmitter for transmitting a coded signal for locking or unlocking the doors of the vehicle, the system further comprising a data receiver for receiving data transmitted by a data transmitter, the data receiver comprising a clock generator for generating a clock signal for use in a data receiver, the clock signal being substantially synchronised with data received by the data receiver, the received data comprising a sync word having a predetermined data frequency and a predetermined value, and being Manchester coded so that each bit of the sync word comprises a logic `1` in one phase of a clock period and a logic `0` in an anti-phase of the clock period, the clock generator comprising:
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means for generating n clocks, each of the n clocks having a frequency which is substantially the predetermined data frequency and being out of phase with an adjacent clock of the n clocks by 1/n of the clock period, each of the n clocks further having one other clock of the n clocks in anti-phase therewith; register means coupled to receive the received data, the register means comprising; n registers, each of the n registers being clocked by a respective one of the n clocks such that the received data is shifted into each register of the n registers in parallel according to the respective clock of the n clocks, each of the n registers having an anti-phase register clocked by an anti-phase clock, n decode logic coupled to respective registers of the n registers, each decode logic for comparing the contents of the respective register with a Manchester coded comparison word having the predetermined value and providing a comparison signal at an output, the comparison signal having a first logic state when the contents of the respective register match the comparison word and a second logic state when the contents respective register do not match the comparison word, and n logic gates for respective registers of the n registers, each logic gate being coupled to the decode logic of the respective register and to the decode logic of its anti-phase register for checking whether the contents of the respective register is inverted compared to the contents of its anti-phase register and for providing an output signal for the respective register, the output signal having a first logic state when the comparison signal for the register has a first logic state and the contents of the register is inverted compared to the contents of its anti-phase register, and a second logic state when the comparison signal of the register has a second logic state and/or the contents of the register is not inverted compared to the contents of its anti-phase register; and logic means for selecting one of the n clocks which clocks a register whose output signal has the first logic state and for providing the selected one of the n clocks as the clock signal for use in the data receiver. - View Dependent Claims (14, 15)
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Specification