Systems and methods for determining clock rates for communicating with processing devices
AssigneeSquare, Inc.
InventorsDavid Terra, Ross Glashan
Life of this patent
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Abstract
A payment terminal such as a payment reader may receive and form electrical connections with an electronic transaction card such as an EMV chip card. The payment terminal may provide a clock signal at a rate that exceeds a specified rate for the EMV chip card. The payment terminal may transmit messages to the EMV chip card and monitor receive messages at a data connection. The payment terminal may determine that the clock rate is excessive based on a timeout of a receive message, an error rate of a receive message, or a receive message indicating that one of the transmit messages was not received by the EMV card. The payment terminal may reduce the clock rate to a rate that is below the specified rate for the EMV chip card.
Claims28
A method for communicating with a processing device, the method comprising:
- providing a clock signal to the processing device from a reader device, the clock signal having a first clock rate;
- providing one or more transmit messages to the processing device from the reader device;
- receiving, at the reader device, one or more receive messages from the processing device;
- determining, at the reader device, that the first clock rate is excessive based on the one or more receive messages indicating that the processing device is unable to correctly respond to the transmit messages when operating at the first clock rate;
- determining, at the reader device, a second clock rate for the clock signal that is less than the first clock rate based on the determination that the first clock rate is excessive;
- providing, from the reader device, the clock signal to the processing device at the second clock rate;
- transmitting one or more additional transmit messages to the processing device from the reader device;
- receiving, at the reader device, one or more additional receive messages from the processing device after transmitting the one or more additional transmit messages;
- determining, at the reader device, that the second clock rate is not excessive based on the one or more additional receive messages indicating that the processing device is able to correctly respond to the transmit messages when operating at the second clock rate;
- and
- processing a transaction with the processing device at the second clock rate after the determination that the second clock rate is not excessive.
A method for communicating with a processing device, the method comprising:
- providing, from a reader device, a clock signal to the processing device, the clock signal having a first clock rate;
- providing, from the reader device, one or more transmit messages to the processing device;
- determining, at the reader device, that the processing device is unable to correctly respond to the transmit messages when operating at the first clock rate;
- determining, at the reader device, a second clock rate for the clock signal that is less than the first clock rate based on the determination that the processing device is unable to correctly respond to the transmit messages when operating at the first clock rate;
- providing, from the reader device, the clock signal to the processing device at the second clock rate;
- and
- processing a transaction with the processing device at the second clock rate.
A reader device for processing transactions with a processing device, the system comprising:
- a clock interface that provides a clock signal from the reader device to the processing device;
- a communication interface that exchanges one or more messages with the processing device;
- a memory having instructions stored thereon;
- a processing unit coupled to the clock interface, the communication interface, and the memory, wherein the processing unit executes the instructions to:
- set the clock signal to a first clock rate;
- provide one or more transmit messages to the communication interface for transmission of the transmit messages to the processing device;
- determine that the processing device is unable to correctly respond to the transmit messages when operating at the first clock rate;
- determine a second clock rate for the clock signal that is less than the first clock rate based on the determination that the processing device is unable to correctly respond to the transmit messages when operating at the first clock rate;
- set the clock signal to the second clock rate;
- provide one or more additional transmit messages to the communication interface for transmission of the additional transmit messages to the processing device;
- determine that the processing device is able to correctly respond to the additional transmit messages when operating at the second clock rate;
- and
- process a transaction with the processing device at the second clock rate after determining that the processing device is able to correctly respond to the additional transmit messages when operating at the second clock rate.
A non-transitory computer-readable storage medium for use in a reader device, the non-transitory computer-readable medium comprising instructions stored therein, which when executed by one or more processors, cause the one or more processors to perform operations comprising:
- causing the reader device to provide a clock signal to a processing device, the clock signal having a first clock rate;
- causing the reader device to provide one or more transmit messages to the processing device;
- determining that the processing device is unable to correctly respond to the transmit messages when operating at the first clock rate;
- determining a second clock rate for the clock signal that is less than the first clock rate based on the determination that the processing device is unable to correctly respond to the transmit messages when operating at the first clock rate;
- causing the reader device to provide the clock signal to the processing device at the second clock rate;
- causing the reader device to provide one or more additional transmit messages to the processing device;
- determining that the processing device is able to correctly respond to the additional transmit messages when operating at the second clock rate;
- and
- processing a transaction with the processing device at the second clock rate after determining that the processing device is able to correctly respond to the additional transmit messages when operating at the second clock rate.
Dependencies are inferred from the claim text.