#Fletcher checksum calculator online generator
The data communication system according to claim 1, said first direct memory accessing address generator includes buffer chaining means allowing multiple discontinuous blocks of data located in different sections of the main memory to be checksummed by linking separate discontinuous blocks together into a single logical group of data.ħ. The data communication system according to claim 4 wherein said arrangement with partial sums computed in adder three and partial carries computed in adder two, provides for said sum-of-sums results to be maintained at the output of adder three after the last byte of the transmitted data is processed and a required number of summing cycles is completed.Ħ.
#Fletcher checksum calculator online series
The data communication system according to claim 1 wherein said checksum calculating means comprises three partial adders, said adders being arranged in series as adders one, two and three to receive transmitted bytes of data so that:Īdder one generates a sum result iteratively, by adding the value of a currently received word with partial sum and partial carry values generated by the adder one in the previously run cycle, yielding the running sums of the transmitted bytes of data Īdder two sums the value of the partial carries from adders one, two and three from the previously run cycle andĪdder three generates a sum-of-sums result by summing the partial sum values from adders one, two, and three from the previously run cycles, yielding the successive running sum of sums of the transmitted bytes.ĥ. The data communication system according to claim 1 wherein said network memory and said main memory comprise a data memory and a control unit which directs address generators to move data to two locations simultaneously and in parallel, one of said locations being the checksum calculating means having the at least one partial adder, and the other one being selected from one of either said network memory or said main memory the direction of said selection being dependent on the direction of data flow.Ĥ. The data communication system according to claim 1 wherein said checksum calculating means complies with a protocol checksum algorithm.ģ. Means of calculating values from the checksum calculation results and placing these values into the data packets.Ģ. A data communication system interactive so as to facilitate a flow of data between at least a main memory and network memory, said data communication system comprising:Īn adder unit having at least one partial adder for calculating checksum values and inputs,Ī checksum calculating means comprises an n-bit data byte delivery means to deliver a series of n-bit data bytes (which is called "checksum calculation results"), derived from input data, to the inputs of said adder unit, and a first direct memory accessing address generator connected to the main memory and a second direct memory accessing address generator connected to the network memory to move data in a form of data packets, each data packet having a first plurality of bytes which specify protocol information, a second plurality of bytes which specify checksum information and a third plurality of bytes which specify a block of data, to flow in one of either of two directions: from the network memory to main memory and simultaneously to checksum calculating means, orĪlternatively, from main memory to network memory and simultaneously to said checksum calculating means and
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