Patent ID: 7409611

Claim:
A circuit comprising: A. test access port having: i. a TDI lead, a TDO lead, a TMS lead, and a TCK lead; ii. a test access port controller having inputs connected to the TMS and TCK leads and having an instruction register and data register control bus output; and iii. a test access port instruction register having a TDI input connected to the TDI lead, control inputs connected to the instruction register and data register control bus output of the test access port controller, and a multiplexer control output; B. a wrapper serial port having: i. a clock lead, a capture lead, a shift lead, an update lead, a transfer lead, a reset lead, a select lead, a WSI lead, and a WSO lead; ii. a wrapper serial port controller having inputs connected to the clock lead, the capture lead, the shift lead, the update lead, the transfer lead, the reset lead, and the select lead, and having an instruction register and data register control bus output; iii. a wrapper serial port instruction register having instruction register control bus inputs, and a WSI input; and iv. wrapper serial port data registers having data register control bus inputs, and a WSI input; C. first multiplexer circuitry having a control input connected to the multiplexer control output of the test access port instruction register, a first bus input connected to the instruction register and data register control bus output of the test access port controller, a second bus input connected to the instruction register and data register control bus output of the wrapper serial port controller, and an instruction register and data register control bus output connected to the wrapper serial port instruction register control bus input and to the wrapper serial port data register control bus inputs; and D. second multiplexer circuitry having a control input connected to the multiplexer control output of the test access port instruction register, a first input connected to the TDO lead, a second input connected to the WSI lead, and an output connected to the WSI input of the wrapper serial port instruction register and the wrapper serial port data registers.