IC first/second surfaces contact points, test control port, parallel scan
This disclosure describes a test architecture that supports a common approach to testing individual die and dies in a 3D stack arrangement. The test architecture uses an improved TAP design to facilitate the testing of parallel test circuits within the die.
1. An integrated circuit die comprising:
(a) a first surface including:
first parallel test input contact points;
first test control input contact points;
a first test data input contact point;
a first test data output contact point; and
first parallel test output contact points;
(b) a second surface including:
second parallel test output contact points coupled to the first parallel test input contact points;
second test control output contact points coupled to the test control input contact points;
a second test data output contact point coupled to the first test data input contact point;
a second test data input contact point coupled to the first test data output contact point; and
second parallel test output contact points coupled to the first parallel test output contact points;
(c) test control port circuitry coupled to:
the test control input contact points;
the first test data input contact point;
the first test data output contact point; and
having control outputs; and
(d) parallel scan circuits having inputs coupled to the first parallel test input contact points, having a control input coupled to the control outputs of the test control port circuitry, and having outputs coupled to the second parallel test output contact points.
2. The integrated circuit die of claim 1 including gating circuitry having a control input coupled to a control output of the test control port circuitry, having an input coupled to a first test control input contact point, and having an output coupled to a second test control output contact point.
3. The integrated circuit die of claim 2 in which:
the first test control input contact points include a test mode select input contact point,
the second test control output contact points include a test mode select output contact point, and
the gating circuitry input is coupled to the a test mode select input contact point, and the gating circuitry output is coupled to the test mode select output contact point.
4. The integrated circuit die of claim 2 in which:
the first test control input contact points include a test mode select input contact point, and a test clock input contact point;
the second test control output contact points include a test mode select output contact point, and a test clock output contact point;
the gating circuitry input is coupled to the test mode select input contact point, the gating circuitry output is coupled to the test mode select output contact point; and
the test clock input contact point is coupled to the test clock output contact point without gating circuitry.
5. The integrated circuit die of claim 2 in which:
the first test control input contact points include a test mode select input contact point, and a test clock input contact point;
the second test control output contact points include a test mode select output contact point, and a test clock output contact point;
the gating circuitry input is a test mode select input coupled to the test mode select input contact point, the gating circuitry output is a test mode select output coupled to the test mode select output contact point; and
the gating circuitry includes a clock input coupled to the test clock input contact point, a clock output is coupled to the test clock output contact point, and a clock control input coupled to a control output of the test control port circuitry.
6. The integrated circuit die of claim 1 including through silicon vias coupled between the first parallel test input contact points and the second parallel test output contact points.
7. The integrated circuit die of claim 1 including through silicon vias coupled between the second parallel test input contact points and the first parallel test output contact points.
8. The integrated circuit of claim 1 in which the outputs of the parallel scan circuits are also coupled to the first parallel test output contact points.
9. The integrated circuit die of claim 1 including parallel output circuits having inputs coupled to the outputs of the parallel scan circuits, having a control input coupled to a control output of the test control port circuitry, and having outputs coupled to the first parallel test output contact points.
10. The integrated circuit of claim 1 in which the first surface is a bottom surface of the die and the second surface is a top surface of the die.
11. The integrated circuit of claim 1 in which test control port circuitry includes:
state machine circuitry having inputs coupled to the test control input contact points and having state control outputs;
an instruction register having an input coupled to the first test data input contact point, having an output coupled to the second test data output contact point, having a control input coupled to the state control outputs, and having instruction control outputs; and
a data register having an input coupled to the first test data input contact point, having an output coupled to the second test data output contact point, having a control input coupled to the state control outputs, and having a control input coupled to the instruction control outputs.