A reception interface unit in a transmission system wherein time series data
is
divided into data groups and a data packet with reproduction specification time
data specifying a time at which each data piece in the data groups should be reproduced,
added to the data groups is transmitted on a transmission bus in a time division
manner. The interface unit has a cycle timer for counting the reference time of
the home device based on the reference time on the transmission bus, a unit for
extracting the reproduction specification time data in the data groups from a signal
received via the transmission bus and storing the reproduction specification time
data in a buffer, a reception buffer for inputting and storing the data pieces
in the data groups in order and reading out the data pieces in the storage order
responsive to a reproduction clock, a match detector for generating a reference
clock pulse if the reference time of the home device matches the reproduction specification
time, and a PLL circuit being responsive to the reference clock pulse for generating
a clock signal which is phase synchronized with the reference clock pulse as the
reproduction clock. When the reference time on the transmission bus changes, the
data stored in the buffer in the reproduction specification time data extraction
unit and the data stored in the reception buffer are all deleted.
