Built in self repair for DRAMs using on-chip temperature sensing and heating
First Claim
1. A memory device which comprises:
- a memory array on a substrate, wherein the memory array is configured to a receive a read/write signal on a read/write line, configured to receive an address on an address bus, configured to provide data to a data bus when the read/write signal indicates a read operation, and configured to store data from the data bus when the read/write signal indicates a write operation, wherein the data on the data bus is stored in a memory location indicated by the address; and
a heating element coupled to the substrate to heat the memory array to a predetermined operating temperature.
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Accused Products
Abstract
A memory device which tests the memory array under typical operating conditions. In one embodiment, the memory device incorporates a heating element to heat the memory array to a predetermined operating temperature, and a BIST (built-in self test) unit to test the memory array at the predetermined operating temperature. This may advantageously provide a method for detecting and repairing faulty memory locations that would not normally test faulty under initial power-up conditions. Broadly speaking, the present invention contemplates a memory device which comprises a memory array and a heating element on a substrate. The memory array is configured to receive a read/write signal on a read/write line, configured to receive an address on an address bus, configured to provide data to a data bus when the read/write signal indicates a read operation, and configured to store data from the data bus when the read/write signal indicates a write operation. The data on the data bus is stored in a memory location indicated by the address on the address bus. The heating element is coupled to the substrate to heat the memory array to a predetermined operating temperature. The memory device may further include a temperature sensor coupled to the substrate and configured to provide a temperature signal indicative of a temperature of the memory array, and a heating control coupled to receive the temperature signal and coupled to responsively regulate power to the heating element.
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Citations
18 Claims
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1. A memory device which comprises:
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a memory array on a substrate, wherein the memory array is configured to a receive a read/write signal on a read/write line, configured to receive an address on an address bus, configured to provide data to a data bus when the read/write signal indicates a read operation, and configured to store data from the data bus when the read/write signal indicates a write operation, wherein the data on the data bus is stored in a memory location indicated by the address; and a heating element coupled to the substrate to heat the memory array to a predetermined operating temperature. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A method for on-chip testing and repairing of memories in a system that contains a heating element, a test circuit, a repair circuit, a memory array, and a plurality of redundant memory locations within the memory array, the method comprising the steps of:
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heating the memory array to a predetermined operating temperature; testing the memory array; determining an original address of a faulty location in the memory array; and repairing the faulty location by using the repair circuit to redirect the original address to an address of a redundant memory location. - View Dependent Claims (8, 9, 10, 11)
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12. An on-chip system for detecting and repairing data retention faults under normal operating conditions, wherein the system comprises:
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a memory array including a plurality of memory cells; a plurality of redundant memory cells coupled to the memory array for replacing faulty memory cells; a heating element coupled to the memory array for heating the memory array to a predetermined operating temperature; a testing unit coupled to the memory array for testing the memory array and determining an original address of a faulty memory cell; and a repair module coupled to the memory array and the testing unit for repairing the faulty memory cell with a redundant memory cell by redirecting the original address to an address of the redundant memory cell. - View Dependent Claims (13, 14, 15)
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16. An on-chip system for detecting and repairing data retention faults, wherein the system comprises:
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a memory array including a plurality of memory cells; a plurality of redundant memory cells coupled to the memory array for replacing faulty memory cells; a heating element coupled to the memory array for heating the memory array; a testing unit coupled to the memory array for testing the memory array and determining an original address of a faulty memory cell; and a repair module coupled to the memory array and the testing unit for repairing the faulty memory cell with a redundant memory cell by redirecting the original address to an address of the redundant memory cell. - View Dependent Claims (17, 18)
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Specification