Method for signaling during a transaction and receiving unit and system for use therewith
View Patent ↗A transmitting device communicates a multi-level clock signal to a receiving device. Changes in the clock level may indicate the start or stop of a transmitting message or delineate fields in the transmitted message. The number of clock pulses received at a particular voltage may indicate further information about the message.
1. A method for delineating a transaction between a transmitting device and a receiving device, the method comprising:
generating a first clock signal with a first voltage level;
transmitting said first clock signal with the first voltage level to the receiving device;
preparing a message for sending during the transaction;
generating a second clock signal with a second voltage level and a plurality of clock pulses;
transmitting the second clock signal with the second voltage level to the receiving device such that the second clock signal with the second voltage level indicates the beginning of the message; and
sending the message to the receiving device, wherein the message has a message type and the number of clock pulses transmitted at said second voltage level indicates said message type.
2. A method according to claim 1 , further comprising:
transmitting the first clock signal with the first voltage level to the receiving device again after transmitting the message to indicate the end of the message.
3. A method according to claim 1 , further comprising transmitting the first clock signal having the first voltage level again during transmission of the message and transmitting the second clock signal having the second voltage level again after transmission of the message to indicate an end of the message.
4. A method according to claim 1 , wherein the message comprises a plurality of fields including a first field and a second field, the method further comprising:
generating a third clock signal with a third voltage level; and
after transmitting the first field, transmitting the third clock signal to the receiving device and simultaneously transmitting the second field such that the third clock signal with the third voltage level indicates the beginning of the second field.
5. A method according to claim 4 , wherein said first field contains information regarding forward error correction.
6. A method for use with a clock signal having a voltage level to interpret a message from a transmitting device received by a receiving device, the method comprising:
receiving the clock signal having the voltage level;
detecting a change in the voltage level of the clock signal from a first voltage level to a second voltage level;
identifying a beginning of the message based on the change in the voltage level of the clock signal; and
identifying a number of clock pulses received at said second voltage level and identifying a type of the message based on the number of clock pulses received at the second voltage level.
7. A method according to claim 6 , further comprising:
detecting a second change in the voltage the clock signal; and
identifying an end of the message based on the second change in the voltage level of the clock signal.
8. A method according to claim 6 , further comprising:
detecting a second change in the voltage level of the clock signal; and
identifying a beginning of a field of the message based on the second change in the voltage level of the clock signal.
9. A method according to claim 8 wherein said field contains forward error correction information.
10. A receiving device for use with a clock signal having a voltage level and a message, the receiving device comprising:
a clock receiver operable to receive the clock signal having the voltage level;
a data input operable to receive the message;
a message detection block coupled to the clock receiver and the data input operable to detect a first change in the voltage level of the clock signal from a first voltage level to a second voltage level and identify a start of the message based on the first change in the voltage level of the clock signal; and
wherein the clock receiver is further operable to identify the number of clock pulses received at said second voltage level and identify a type of the message based on the number of clock pulses received at the second voltage level.
11. A receiving device according to claim 10 , wherein the clock receiver is further operable to generate a binary clock signal and a start of message signal based on said received clock signal.
12. A receiving device according to claim 10 , wherein the clock receiver is further operable to detect a second change in the voltage level of the clock signal and generate a field signal indicative of a field of the message based on the second change in the voltage level.
13. A system for communicating a message from a transmitting device to a receiving device, the system comprising:
a transmitting device including a multi-level clock generator operable to generate a clock signal having a voltage level and including a data output operable to transmit a message;
a receiving device coupled to the transmitting device and operable to receive the clock signal having the voltage level and to detect a first change in the voltage level of the clock signal from a first voltage level to a second voltage level and identify a start of the message based on the first change in the voltage level of the clock signal; and
wherein the receiving device is further operable to identify the number of clock pulses received at said second voltage level and identify a type of the message based on the number of clock pulses received at the second voltage level.
14. A system according to claim 13 , further comprising a serial connection for coupling the receiving device to the transmitting device.
15. A system according to claim 13 , further comprising a parallel connection for coupling the receiving device to the transmitting device.
16. A system according to claim 13 , wherein the receiving device is further operable to detect a second change in the voltage level of the clock signal to identify a beginning of a field of the message based on the identification of the second voltage change.
17. A method for delineating a transaction between a transmitting device and a receiving device, the method comprising:
generating a first clock signal with a first voltage level;
transmitting said first clock signal with the first voltage level to the receiving device;
preparing a message having first and second fields for sending during the transaction;
generating a second clock signal with a second voltage level;
transmitting the second clock signal with the second voltage level to the receiving device such that the second clock signal with the second voltage level indicates the beginning of the first field of the message;
sending the first field of the message to the receiving device;
generating a third clock signal with a third voltage level; and
after transmitting the first field of the message, transmitting the third clock signal to the receiving device and simultaneously transmitting the second field of the message such that the third clock signal with the third voltage level indicates the beginning of the second field of the message.
18. A method according to claim 17 , wherein said first field of the message contains information regarding forward error correction.