Input/output device configured for minimizing I/O read operations by copying values to system memory
AssigneeAdvanced Micro Devices, Inc.
InventorsRobert Alan Williams, Jeffrey Dwork
Life of this patent
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Abstract
An I/O device configured for accessing a system memory via a peripheral bus minimizes I/O read accesses required by a CPU, by copying an interrupt status value from its interrupt register to a prescribed location in the system memory. Once the interrupt status value is copied into system memory, the I/O device generates an interrupt to notify the CPU of an interrupt condition requiring servicing. Hence, the interrupt status value stored in system memory enables the CPU to service the interrupt based on reading the interrupt status value from system memory, eliminating the necessity of performing an I/O read operation of the interrupt register within the I/O device via a peripheral bus.
Claims13
A method in a computing system having a central processing unit (CPU), a system memory, and an Input/Output (I/O) device configured for accessing the system memory via a peripheral bus, the method comprising:
- updating by the I/O device an interrupt status value of an interrupt register within the I/O device based on the I/O device detecting at least one interrupt condition;
- copying the interrupt status value by the I/O device to a prescribed location in the system memory;
- generating by the I/O device an interrupt for notifying the CPU of the at least one interrupt condition;
- and
- servicing the interrupt by the CPU reading the interrupt status value from the prescribed location in the system memory.
An Input/Output (I/O) device controllable by a Central Processing Unit (CPU) and configured for accessing a system memory via a peripheral bus, the I/O device comprising:
- an interrupt register configured for storing an interrupt status value;
- and
- interrupt logic configured for:
- (1) updating the interrupt status value in the interrupt register and copying the interrupt status value to a prescribed location in the system memory based on detecting at least one interrupt condition, and
- (2) generating an interrupt upon copying the interrupt status value to the prescribed location, enabling the CPU to service the interrupt based on reading the interrupt status value from the prescribed location.
Dependencies are inferred from the claim text.