Fault tolerant communication channel

An apparatus comprising:

• a first device;
• a second device;
• a communication channel between the first device and the second device, the communication channel including a first data path for transmitting from the first device to the second device, a second data path for transmitting from the second device to the first device, and a clock signal path for transmitting a clock signal;
• wherein the first device is configured to transmit information over the first data path to the second device;
• wherein the second device is configured to echo back the information to the first device over the second data path;
• wherein the first device is configured to compare the echoed back information to the information and to send a valid signal across the communication channel responsive to a determination of a successful transfer based on the compare;
• wherein the second device is configured to respond to the valid signal to send a valid acknowledge signal across the communication channel;
• wherein the first device is configured to stop sending the valid signal responsive to the valid acknowledge signal;
• and
• wherein the second device is configured to stop sending the valid acknowledge signal responsive to determining the first device has stopped sending the valid signal.

An apparatus comprising:

• a transmitting device;
• a receiving device;
• a first data path couples the transmitting device to the receiving device, a second data path couples the receiving device to the transmitting device, and a clock signal path for transmitting a clock signal;
• wherein the receiving device is configured to echo back data received over the first data path to the transmitting device over the second data path while at least a portion of the data is still being received over the first data path;
• wherein the transmitting device is configured to send a valid signal across the first data path responsive to the echoed back data matching data transmitted by the transmitting device;
• wherein the receiving device is configured to respond to the valid signal to send a valid acknowledge signal across the second data path;
• wherein the transmitting device is configured to stop sending the valid signal responsive to the valid acknowledge signal;
• and
• wherein the receiving device is configured to stop sending the valid acknowledge signal responsive to determining the transmitting device has stopped sending the valid signal.