Level two first-in-first-out transmission

A data packet transmission method, comprising:

• receiving, at a multiplexer, first data from a processor;
• receiving, from the multiplexer, second data at a transmit circuit for transmission to a far end device, the second data based on the first data;
• initiating, using the transmit circuit, transmission to the far end device of a first data packet, the first data packet based on the second data;
• receiving, at a state machine, one or more operational codes from the processor;
• causing, using the state machine, a checksum circuit to alter a checksum value of the first data packet being transmitted by the transmit circuit;
• and
• causing, using the state machine, the transmit circuit to preempt transmission of the first data packet and begin transmitting a second data packet once the checksum value so altered has been transmitted from the transmit circuit.

A system on a chip, comprising:

• a programmable real-time processor;
• a state machine connected to the programmable real-time processor through a broadside interface, wherein the state machine is configured to receive operational codes from the programmable real-time processor;
• a checksum circuit;
• a multiplexer connected to the programmable real-time processor, the state machine and the checksum circuit, wherein the multiplexer is configured to receive first data from the programmable real-time processor;
• and
• a transmit circuit connected to the multiplexer, wherein the transmit circuit configured to receive second data from the multiplexer for transmission to a far end device, wherein the second data is based on the first data,
• wherein the state machine is further configured to, responsive receiving one or more operational codes from the programmable real-time processor:
• cause the checksum circuit to alter a checksum value of a first data packet being transmitted by the transmit circuit;
• and
• cause the transmit circuit to preempt transmission of the first data packet and begin transmitting a second data packet once the checksum value so altered has been transmitted from the transmit circuit.