Patent ID: 6128308
Filing Date: 2000-10-03
Classification: H04L

Abstract:
A method for monitoring a storage of a data frame in a buffer memory, comrising:storing the frame in a random access memory at a prescribed location using a write controller operating according to a first clock;supplying a first signal to a first counter based on the storing step, the first counter configured for changing a single bit of a first counter value in response to each received first signal;reading the first frame from the random access memory using a read controller operating according to a second clock independent from the first clock;supplying a second signal to a second counter based on the reading step, the second counter configured for changing a single bit of a second counter value in response to each received second signal; andcomparing the first and second counter values to determine a presence of a stored data frame in the random access memory, whereinthe comparing step includes generating a comparison result indicating one of a presence of less than one complete frame in the random access memory and the presence of at least one frame as said stored data frame in the random access memory, andthe storing step comprises:receiving the frame from a host computer bus according to a host computer clock as the first clock;reserving a first portion of the prescribed memory location for header information corresponding to the frame;writing the frame at a second portion of the prescribed memory location; andfollowing the writing step, updating the first portion with the header information.