Method and apparatus for testing a multi-die integrated circuit device

1. A method for scan chain testing of a multi-chip module including a plurality of integrated circuit dice, at least two of the integrated circuit dice being of a same first type and at least one of the integrated circuit dice being of a second type different from the first type, the method comprising:

separately applying a first boundary scan test stream to each integrated circuit die of the first type of integrated circuit dice, the separately applying including configuring the first boundary scan test stream to test each integrated circuit die of the first type of integrated circuit dice in both transmit and receive directions by simulating loopback of transmit and receive pins of the respective integrated circuit die of the first type of integrated circuit dice; and

separately applying a second boundary scan test stream to each integrated circuit die of the second type of integrated circuit dice, the separately applying including configuring the second boundary scan test stream to test each integrated circuit die of the second type of integrated circuit dice in both transmit and receive directions by simulating loopback of transmit and receive pins of the respective integrated circuit die of the second type of integrated circuit dice.

2. The method of claim 1 wherein the applying a first boundary scan test stream and the applying a second boundary scan test stream are performed by merging the first boundary scan test stream and the second boundary scan test stream and applying the merged streams.

3. The method of claim 2 wherein applying the merged streams comprises applying, seriatim, portions of the merged streams corresponding to the first boundary scan test stream and the second boundary scan test stream.

4. The method of claim 2 wherein applying the merged streams comprises applying, in parallel, portions of the merged streams corresponding to the first boundary scan test stream and the second boundary scan test stream.

5. The method of claim 1 wherein, when the respective integrated circuit die has a first boundary scan register chain of a certain length and is connected for transmission to and reception from another integrated circuit die having a second boundary scan register chain of the certain length, configuring the one of the boundary scan test streams to simulate loopback of transmit and receive pins of the respective integrated circuit die comprises simulating direct loopback of the transmit and receive pins.

6. The method of claim 1 wherein, when the respective integrated circuit die has a first boundary scan register chain of a certain length and is connected for transmission to and reception from another integrated circuit die having a second boundary scan register chain of a second length different from the certain length, configuring the one of the boundary scan test streams to simulate loopback of transmit and receive pins of the respective integrated circuit die comprises simulating delayed loopback of the transmit and receive pins.

7. The method of claim 6 wherein the simulating delayed loopback of the transmit and receive pins comprises adding idle cycles to a shorter one of the first and second boundary scan register chains.

8. The method of claim 1 further comprising applying a third boundary scan test stream to the multi-chip module as a whole.

9. Testing apparatus for scan chain testing of a multi-chip module including a plurality of integrated circuit dice, at least two of the integrated circuit dice being of a same first type and at least one of the integrated circuit dice being of a second type different from the first type, each respective integrated circuit die having a respective test access port, the testing apparatus comprising:

a test interface that couples to each respective test access port; and

a controller configured to:

separately apply, via the test interface, a first boundary scan test stream to a respective test access port of each integrated circuit die of the first type of integrated circuit dice, the separately applying including configuring the first boundary scan test stream to test each integrated circuit die of the first type of integrated circuit dice in both transmit and receive directions by simulating loopback of transmit and receive pins of the respective integrated circuit die of the first type of integrated circuit dice; and

separately apply, via the test interface, a second boundary scan test stream to a respective test access port of each integrated circuit die of the second type of integrated circuit dice, the separately applying including configuring the second boundary scan test stream to test each integrated circuit die of the second type of integrated circuit dice in both transmit and receive directions by simulating loopback of transmit and receive pins of the respective integrated circuit die of the second type of integrated circuit dice.

10. The testing apparatus of claim 9 wherein the controller is configured to apply, seriatim, the respective first boundary scan test stream to the respective test access port of the first type of integrated circuit dice and the respective second boundary scan test stream to the respective test access port of the second type of integrated circuit dice.

11. The testing apparatus of claim 9 wherein the controller is configured to apply, in parallel, the respective first boundary scan test stream to each respective test access port of the first type integrated circuit dice and the respective second boundary scan test stream to each respective test access port of the second type of integrated circuit dice.

12. The testing apparatus of claim 9 wherein, when the respective integrated circuit die has a first boundary scan register chain of a certain length and is connected for transmission to and reception from another integrated circuit die having a second boundary scan register chain of the certain length, the controller is configured to simulate direct loopback of transmit and receive pins of the respective integrated circuit die.

13. The testing apparatus of claim 9 wherein, when the respective integrated circuit die has a first boundary scan register chain of a certain length and is connected for transmission to and reception from another integrated circuit die having a second boundary scan register chain of a second length different from the certain length, the controller is configured to simulate delayed loopback of transmit and receive pins of the respective integrated circuit die.

14. The testing apparatus of claim 13 wherein the controller is configured to delay loopback of the transmit and receive pins by adding idle cycles to a shorter one of the first and second boundary scan register chains.

15. The testing apparatus of claim 9 wherein the controller is configured to apply a third boundary scan test stream to a test access port of the multi-chip module as a whole.

16. A multi-chip module comprising:

a plurality of integrated circuit dice, each respective integrated circuit die comprising a respective boundary scan register chain and a respective test access port for the respective boundary scan register chain of the respective integrated circuit die;

a test access port for testing of a boundary scan register chain spanning the multi-chip module as a whole; and

a plurality of input/output pins; wherein:

a first subset of the plurality of input/output pins includes first pins configurable for use for run-time functional signals during run-time operation of the multi-chip module, and configurable in a test mode as pins of a device-wide test access port; and

a second subset of the plurality of input/output pins, separate from the first subset of the plurality of input/output pins, the second subset of the plurality of input/output pins including second pins configurable for use for run-time functional signals during run-time operation of the multi-chip module, and configurable in the test mode as pins of respective individual test access ports for each of the respective integrated circuit dice.