Semiconductor device, electronic device, and self-diagnosis method for semiconductor device
AssigneeRenesas Electronics Corporation
InventorTakuro NISHIKAWA
Life of this patent
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Abstract
A semiconductor device addresses to a problem in which a current consumption variation rate increases during BIST execution causing resonance noise generation in a power supply line. The semiconductor device includes a self-diagnosis control circuit, a scan target circuit including a combinational circuit and a scan flip-flop, and an electrically rewritable non-volatile memory. A scan chain is configured by coupling a plurality of the scan flip-flops. In accordance with parameters stored in the non-volatile memory, the self-diagnosis control circuit can change a length of at least one of a scan-in period, a scan-out period and a capture period, and can also change a scan start timing.
Claims7
1-11. (canceled)
An electronic device, comprising:
- a first semiconductor device;
- a second semiconductor device;
- a power supply circuit;
- and
- a passive element,
- wherein the first and second semiconductor devices each include a self-diagnosis control circuit, a scan target circuit, and an electrically rewritable non-volatile memory, the scan target circuit including a plurality of scan flip-flops and a selector for switching between outputs of the scan flip-flops,
- wherein, in each of the first and second semiconductor devices, the scan flip-flops are coupled to configure a scan chain, and
- wherein the self-diagnosis control circuit controls the selector in accordance with data stored in the non-volatile memory such that the first and second semiconductor devices have a same scan chain configuration and such that the first and second semiconductor devices start scanning at different times.
A self-diagnosis method for a semiconductor device including a self-diagnosis control circuit, a scan target circuit and an electrically rewritable non-volatile memory, the method comprising the steps of:
- (a) after a reset release, having the self-diagnosis control circuit read parameters from the non-volatile memory and set a scan chain configuration for the scan target circuit;
- (b) after a predetermined amount of time, performing a scan test on the scan target circuit;
- and
- (c) after the scan test, comparing an expected value stored in the non-volatile memory and a scan test result.
Dependencies are inferred from the claim text.