Abstract: A data communication circuit buffers data between a shared resource and a plurality of data communication interfaces through a plurality of respective first-in-first-out ("FIFO") buffers. The data is divided into multiple-bit data frames having a start and an end. The circuit maintains a priority level for each FIFO buffer and initializes the priority level of each FIFO buffer to a first priority level. The circuit passes bits of the multiple-bit data frames from the shared resource to respective ones of the FIFO buffers in a buffer order which is based on the priority level of each FIFO buffer. The circuit passes the bits from the FIFO buffers to the respective data communication interfaces and selectively increases the priority level of each FIFO buffer to a second, higher priority level as a function of a level the bits within the FIFO buffer and whether the end of at least one data frame is stored in the FIFO buffer.

Abstract: A multipoint data modem communication system (10) includes a master modem (12) and a plurality of remote modems (14, 16 and 18). During an initial, remote-to-master transmission, a relatively long training sequence is transmitted and receiver parameter and equalizer coefficients are stored in a storage unit (156) in the master modem (12). During subsequent transmissions a relatively short training sequence which synchronizes the master modem receiver timing and also identifies the transmitting remote modem is applied. In the master modem an interpolation filter based on a ninth order Lagrange interpolation formula is located between an analog-to-digital converter (84) and a band-pass filter (92). Coefficients for the interpolation filter are calculated using a residual time shift value which is computed using a DFT calculator (96) which is coupled to a phase segment detector (142) and a phase-to-time-shift converter (146).