Granted Patent B2

US 11,017,135 · App. 15/667,363 · Granted May 25, 2021

Inventor: Athmanathan Vaidyanathan (Gilbert, AZ)

Assignee: MICROCHIP TECHNOLOGY INCORPORATED

G06F30/30G01R31/3177G01R31/31704G01R31/31723G01R31/31727G01R31/318544G01R31/318558

Abstract

Claims (21)

1. A system for scanning a circuit, the system comprising:

a plurality of flip-flops;

a plurality of latches interleaved between the flip-flops;

a plurality of multiplexers interleaved between the flip-flops and the latches;

scan logic configured to control the multiplexers to load a plurality of initial test data into the flip-flops and the latches;

wherein:

a first pair of latches are interleaved between a first pair of consecutive flip-flops;

the multiplexers are configured to propagate a plurality of resulting test data between the flip-flops and latches, the resulting test data resulting from operation of the circuit on the initial test data;

a variable number of latches are interleaved between a plurality of pairs of flip-flops of the plurality of flip-flops, including:

a first set of latches interleaved between second pair of flip-flops; and

a second set of latches interleaved between a third pair of flip-flops;

the scan logic is further configured to:

enable a first number of latches of the first set of latches for a test; and

enable a second number of latches of the second set of latches of the test;

the first number of latches and the second number of latches are different;

the first number of latches are enabled with a first enablement signal;

the second number of latches are enabled with a second enablement signal; and

the first enablement signal and the second enablement signal are different enablement signals.

2. The system of claim 1 , wherein a single latch is interleaved between a second pair of flip-flops of the plurality of flip-flops.

3. The system of claim 1 , wherein no latch is interleaved between a second pair of flip-flops of the plurality of flip-flops.

4. The system of claim 1 , wherein the first pair of consecutive flip-flops are a master-slave pair of flip-flops.

Assignments (17)

Continuity (3)