PURPOSE: To reduce the current consumption by connecting a terminal resistance to a transmission line for suppression of reflection only when the signal level varies on the transmission line.
CONSTITUTION: The signal level of an input/output circuit 5 of a DRAM chip 2 is decided by the exclusive power supply VHO1 and VOL1. These VOH1 and VOL1 can be applied from outside of the chip 2 and also can be generated in the chip 2. Under such conditions, a termination circuit 1 is set at the resistance value equal to the characteristic impedance of a transmission line 4 only when output 01 received from the circuit 5 is changed and otherwise set at a high resistance level. As a result, a current flows to the circuit 1 from a terminal power voltage VTT only in a signal transition state and no current flows to the circuit 1 in other periods. Thus the current consumption can be reduced.
ETO JUN
NAKAGOME YOSHINOBU
AOKI MASAKAZU
