Patent ID: 8065577

Claim:
An integrated circuit comprising: A. a test protocol in lead, a test clock in lead, a test enable in lead, a test data in lead, and a test data out lead; B. first controller circuitry including: i. test control register circuitry having a serial data input, register control inputs, a serial data output, and control bus outputs; ii. test control state machine circuitry having a test protocol input connected with the test protocol in lead, a test clock input connected with the test clock in lead, a test enable input connected with the test enable in lead, and control inputs connected to the control bus outputs, the state machine having a shift distributor and collector output, a capture collector output, a shift parallel scan path output, and a capture parallel scan path output, the state machine having control outputs connected to the register control inputs; and iii. multiplexer circuitry having control inputs connected to the control bus outputs, a first serial data input connected to the serial data output of the test control register circuitry, a second serial data input, and a serial data output; and C. second controller circuitry including: i. test control register circuitry having a serial data input, register control inputs, a serial data output, and control bus outputs; ii. test control state machine circuitry having a test protocol input connected with the test protocol in lead, a test clock input connected with the test clock in lead, a test enable input, and control inputs connected to the control bus outputs, the state machine having a shift distributor and collector output, a capture collector output, a shift parallel scan path output, and a capture parallel scan path output, the state machine having control outputs connected to the register control inputs; and iii. multiplexer circuitry having control inputs connected to the control bus outputs, a first serial data input connected to the serial data output of the test control register circuitry, a second serial data input, and a serial data output.