| 摘要 |
An integrated circuit comprises a serial data input pin and a serial data output pin, on-chip functional circuitry and test logic, a test access port controller connected to effect communication of serial data across the chip boundary via said input and output pins, the test access port controller being connectable to the test logic in a first mode of operation to effect communication of serial test data off-chip, a data adaptor which is connectable to the input and output pins via the test access port controller in a second mode of operation, wherein the data adaptor comprises a first interface for communicating data in the form of serial bits to and from said test access port controller under the control of a first clock signal and a second interface for communicating data in the form of successive sets of parallel data and control signals to and from said on-chip functional circuitry under the control of a second clock signal generated independently of said first clock signal, and wherein said data adaptor comprises data storage means for holding data received in the data adaptor to take into account differences between the first and second clock signals. <IMAGE> |
