Reduced power load/store queue searching mechanism
AssigneeSTMicroelectronics (Beijing) R&D Co., Ltd.
InventorsKai-Feng Wang, Hong-Xia Sun, Yong-Qiang Wu
Life of this patent
Estimating the term…
Abstract
A comparison circuit can reduce the amount of power consumed when searching a load queue or a store queue of a microprocessor. Some embodiments of the comparison circuit use a comparison unit that performs an initial comparison of addresses using a subset of the address bits. If the initial comparison results in a match, a second comparison unit can be enabled to compare another subset of the address bits.
Claims18
A comparison circuit that compares a first address with a second address, the second address being stored in a load queue and/or store queue of a microprocessor, the comparison circuit comprising:
- a first comparison unit that compares a first subset of bits of the first address with a corresponding second subset of bits of the second address to produce a first comparison result indicating whether the first subset of bits is equal to the second subset of bits;
- and
- a second comparison unit coupled to the first comparison unit to receive the first comparison result, wherein the second comparison unit is enabled and disabled based on the first comparison result, wherein, when the second comparison unit is enabled, the second comparison unit compares a third subset of bits of the first address with a corresponding fourth subset of bits of the second address.
A method of comparing a first address with a second address, the second address being stored in a load queue and/or store queue of a microprocessor, the method comprising:
- comparing a first subset of bits of the first address with a corresponding second subset of bits of the second address;
- and
- when the first subset of bits is equal to the second subset of bits, comparing a third subset of bits of the first address with a corresponding fourth subset of bits of the second address.
Dependencies are inferred from the claim text.