US Patent 7675769 Semiconductor integrated circuit

In a semiconductor integrated circuit having a register file of a multiport configuration, a first holding circuit 20A is dedicated to a first functional block having one first write port section 21AW and two first read port sections 21AR1 and 21AR2. A second holding circuit 30B is dedicated to a second functional block having one second write port section 31AW and one second read port section 31BR. When it is necessary to read data held in the first holding circuit 20A from the second read port section 31BR, for example, a data interchange operation is performed as follows. After the data of the second holding circuit 30B is latched in a latch circuit 40, the data of the first holding circuit 20A is transferred to the second holding circuit 30B, and then the data of the second holding circuit 30B latched in the latch circuit 40 is transferred to the first holding circuit 20A. Thus, the area necessary to provide a register file is significantly reduced.