Patent ID: 7177280

Claim:
A data transfer processing apparatus for transmitting data supplied from a preceding circuit over a serial bus on a packet basis, comprising: holding means for holding a data transfer variable; buffer means for temporarily holding data supplied from said preceding circuit and outputting the temporarily held data in a predetermined transmission timed relation; count means for counting a number of data packets to be transmitted over said serial bus from said buffer means during a predetermined transfer period; transmission control means for, on the basis of said data transfer variable held in said holding means and a count value of said count means, increasing or decreasing the number of data packets to be transmitted over said serial bus from said buffer means; monitor means for monitoring a data quantity held in said buffer means; and data supply quantity indicating means for indicating to said preceding circuit a data supply quantity to be supplied to a receiving apparatus on the basis of said data quantity in said buffer means monitored by said monitor means and said data transfer variable held in said holding means.