An internal bus testing device for a semiconductor integrated circuit in which
an internal bus control circuit and a plurality of modules are linked by a plurality
of internal buses. The internal bus testing device includes an area selector which
causes the internal bus control circuit to select an address area corresponding
to one of the plurality of internal buses. An area address setting unit sets the
internal bus control circuit in an internal bus test mode in response to an internal
bus test start signal, the area address setting unit storing a state setting signal
and a predetermined address value indicating the address area. A control unit supplies,
at a start of an internal bus test, the address value from the area address setting
unit to the area selector by transmitting the state setting signal from the area
address setting unit to the area selector.