Patent ID: 7256601

Claim:
An integrated circuit comprising: A. functional circuits including: i. functional bond pads connected to the functional circuits; ii. a first group of parallel scan paths circuits connected to the functional circuits, each of the first group of parallel scan path circuits having a serial input and a serial output; iii. a first scan distributor circuit having a serial input connected to a first functional bond pad, a serial output, and parallel outputs, each parallel output being connected to an input of a parallel scan path circuit of the first group; iv. a first scan collector circuit having a serial output connected to a second functional bond pad separate from the first functional bond pad, a serial input, and parallel inputs, each parallel input being connected to an output of a respective parallel scan circuit of the first group; and v. a first controller having a first serial input and a first serial output each connected to a functional bond pad, first control outputs connected to the first group of parallel scan path circuits, the first scan distributor circuit, and the first scan collector circuit, a second serial output, a second serial input, a multiplexer control output, and a demultiplexer control output; B. core circuits separate from the functional circuits including: i. core bond pads; ii. a second group of parallel scan paths circuits connected to the core circuits, each of the second group of parallel scan path circuits having a serial input and a serial output; iii. a second scan distributor circuit having a serial input connected to a first core bond pad and parallel outputs, each parallel output being connected to an input of a parallel scan path circuit of the second group; iv. a second scan collector circuit having a serial output connected to a second core bond pad separate from the first core bond pad and parallel inputs, each parallel input being connected to an output of a respective parallel scan circuit of the second group; and v. a second controller having a serial input connected to a third core bond pad and a serial output connected to a fourth core bond pad, second control outputs connected to the second group of parallel scan path circuits, the second scan distributor circuit, and the second scan collector circuit; C. a multiplexer having a functional input, a serial input connected to the serial output of the first scan distributor circuit, a control input connected to the multiplexer control output of the first controller, and an output connected to the first core bond pad; D. a demultiplexer having an input connected to the second core bond pad, a functional output, a serial output connected to the serial input of the first scan collector circuit, and a control input connected to the demultiplexer control output of the first controller; and E. connections between the second serial output and the third core bond pad and between the second serial input and the fourth core bond pad.