| 摘要 |
PURPOSE:To execute the observation of an in-LSI signal in the device independently from a device scan function by holding scan control information and outputting a signal of a designated FF to the outside of an integrated circuit without supplying the scan control information from the outside of the integrated circuit. CONSTITUTION:Byte and bit addresses of an object FF, and an ENBL-20 are set in advance to BYT-18, BIT-19, and an 'H' level, respectively by using a device scan function. When a regular scan operation is ended and SENBL of an object LSI becomes an 'L' level, outputs of enable logic 7, 8 become 'H', and from the BYT-18 and the BIT-19 registers, an address of an observation object FF is supplied to a BYTDEC-11 and a BITDEC-12 through a BYTSEL-9 and a BTTSEL-10, and an observing signal is outputted to an SOD 6 through SODGENs 16, 17. In this case, as for SIDGENs 13, 14, the operation is inhibited, and the object FF is in a state that a regular logical operation can be executed. |
