A test circuit according to the present invention includes: a synthesis circuit that synthesizes a first test result signal output from a first test target circuit in response to a test instruction, and a second test result signal output from a second test target circuit in response to the test instruction; an inter-block delay generation circuit that delays the second test result signal with respect to the first test result signal; and a test result holding circuit that holds a synthesized test result signal every predetermined timing, the synthesized test result signal being output from the synthesis circuit.
1. A test circuit, comprising:
a synthesis circuit that synthesizes a first test result signal output from a first test target circuit in response to a test instruction, and a second test result signal output from a second test target circuit in response to the test instruction;
an inter-block delay generation circuit that delays the second test result signal with respect to the first test result signal; and
a test result holding circuit that holds a synthesized test result signal every predetermined timing, the synthesized test result signal being output from the synthesis circuit.
2. The test circuit according to claim 1 , wherein the inter-block delay generation circuit supplies an operation clock delayed from an operation clock for the first test target circuit, to the second test target circuit.
3. The test circuit according to claim 1 , wherein the inter-block delay generation circuit outputs the second test result signal delayed from the first test result signal.
4. The test circuit according to claim 3 , wherein the inter-block delay generation circuit delays and outputs the second test result signal when one of a rising edge and a falling edge of the first test result signal is synchronized with one of a rising edge and a falling edge of the second test result signal.
5. The test circuit according to claim 1 , wherein the inter-block delay generation circuit delays and outputs the second test result signal when one of a rising edge and a falling edge of the first test result signal is synchronized with one of a rising edge and a falling edge of the second test result signal.
6. The test circuit according to claim 1 , wherein the test result holding circuit counts the synthesized test result signal every predetermined timing, and holds a count value.
7. The test circuit according to claim 1 , wherein the synthesis circuit outputs an exclusive OR of the first test result signal and the second test result signal, as the synthesized test result signal.
8. The test circuit according to claim 1 , wherein the first test target circuit and the second test target circuit output the same test result signal in response to the same test instruction.
9. The test circuit according to claim 1 , wherein the test instruction is output from an arithmetic section connected with each of the first test target circuit and the second test target circuit.
10. The test circuit according to claim 1 , wherein the first test target circuit and the second test target circuit are provided separately from a circuit comprising a scan chain circuit.
11. The test circuit according to claim 2 , wherein the first test target circuit and the second test target circuit output the same test result signal in response to the same test instruction.
12. The test circuit according to claim 3 , wherein the first test target circuit and the second test target circuit output the same test result signal in response to the same test instruction.
13. The test circuit according to claim 4 , wherein the first test target circuit and the second test target circuit output the same test result signal in response to the same test instruction.
14. The test circuit according to claim 5 , wherein the first test target circuit and the second test target circuit output the same test result signal in response to the same test instruction.
15. The test circuit according to claim 6 , wherein the first test target circuit and the second test target circuit output the same test result signal in response to the same test instruction.