Method and apparatus for a microprocessor to enter and exit a reduced power consumption state
First Claim
1. A method for enabling a microprocessor to enter and exit a reduced power consumption state without degradation to instructions being executed by said microprocessor prior to entering said reduced power consumption state, said method comprising the steps of:
- a) detecting a first System Management Mode interrupt request for said microprocessor to enter said reduced power consumption state;
b) asserting a first signal upon detecting said first System Management Mode interrupt, wherein said signal causes said microprocessor to complete executing instructions pending in said microprocessor;
c) intercepting instructions in said microprocessor'"'"'s instruction pipeline prior to said microprocessor entering said reduced power consumption state;
d) storing said intercepted instructions in said microprocessor;
e) flushing said instruction pipeline, so that instructions pending in said instruction pipeline are not executed as said microprocessor enters said reduced power consumption state;
f) executing a shutdown instruction in said microprocessor, such that said microprocessor enters said reduced power consumption state, wherein said execution of said shutdown instruction causes current levels in said microprocessor to be gradually reduced as said microprocessor enters said reduced power consumption state;
g) executing a resume instruction in said microprocessor as microprocessor exits said reduced power consumption state; and
h) restoring said intercepted instructions to said microprocessor upon said microprocessor exiting said reduced power consumption state.
1 Assignment
0 Petitions
Accused Products
Abstract
A method and apparatus for placing a microprocessor in and out of a reduced power consumption state utilizing system interrupts in a computer system. The method of the present invention intercepts instructions being executed by the processor before placing the processor in a reduced power consumption state. On a request for the processor to exit the reduced power consumption state, the method of the present inventions allows the processor to execute pre-determined resume instructions to wait out any voltage level fluctuations in the processor as it exits the reduced power consumption state, before allowing the processor to continue execution of the instructions intercepted prior to placing the processor in the reduced power consumption state.
48 Citations
20 Claims
-
1. A method for enabling a microprocessor to enter and exit a reduced power consumption state without degradation to instructions being executed by said microprocessor prior to entering said reduced power consumption state, said method comprising the steps of:
-
a) detecting a first System Management Mode interrupt request for said microprocessor to enter said reduced power consumption state; b) asserting a first signal upon detecting said first System Management Mode interrupt, wherein said signal causes said microprocessor to complete executing instructions pending in said microprocessor; c) intercepting instructions in said microprocessor'"'"'s instruction pipeline prior to said microprocessor entering said reduced power consumption state; d) storing said intercepted instructions in said microprocessor; e) flushing said instruction pipeline, so that instructions pending in said instruction pipeline are not executed as said microprocessor enters said reduced power consumption state; f) executing a shutdown instruction in said microprocessor, such that said microprocessor enters said reduced power consumption state, wherein said execution of said shutdown instruction causes current levels in said microprocessor to be gradually reduced as said microprocessor enters said reduced power consumption state; g) executing a resume instruction in said microprocessor as microprocessor exits said reduced power consumption state; and h) restoring said intercepted instructions to said microprocessor upon said microprocessor exiting said reduced power consumption state. - View Dependent Claims (4, 5, 6)
-
-
2. The method of claim I wherein said step (h) includes the step of restoring said intercepted instructions, so that said microprocessor is restored back to a state said microprocessor was in prior to entering said reduced power consumption state.
-
3. The method of claim I wherein said step (g) includes the step of detecting a second System Management Mode interrupt for said microprocessor to exit said reduced power consumption state.
-
7. In a computer system having a processing means coupled to peripheral devices, said processing means executing instructions to said peripherals devices, wherein said processing means enters and exits a reduced power consumption state, said computer system comprising:
-
a shutdown means responsive to a first System Management Mode interrupt for transitioning said processing means to a reduced power consumption state, said shutdown means including shutdown routines which cause current levels in the processing means to be gradually reduced as the processing means enters the reduce power consumption state, said shutdown means coupled to said processing means; an intercepting means for intercepting instructions being executed in said processing means prior to said processing means entering said reduced power consumption state, said intercepting means coupled to said shutdown means; a storing means coupled to said shutdown means for storing said intercepted instructions in said processing means, so that said instructions are not executed in said processing means while said processing means is in said reduced power consumption state; exiting means responsive to a second System Management Mode interrupt for exiting said reduced power consumption state, said exit means includes exit routines which are executed by said processing means when exiting said reduced power consumption state, said exiting means coupled to said processing means; and a restoring means coupled to said exiting means for restoring instructions intercepted in said processing means prior to said processing means entering said reduced power consumption state. - View Dependent Claims (8, 9, 10, 11, 12)
-
-
13. An apparatus for enabling a microprocessor to enter and exit a reduced power consumption state in a computer system without degradation in instructions being executed by said microprocessor prior to said microprocessor entering said reduced power consumption state, said apparatus comprising:
-
a shutdown circuit coupled to said microprocessor, said shutdown circuit activated by a first signal upon said microprocessor detecting a first System Management Mode interrupt, wherein said shutdown circuit includes shutdown routine executed by said microprocessor and causing current levels in the microprocessor to be gradually reduced as said microprocessor enters said reduced power consumption state; a resume circuit coupled to said microprocessor, wherein said resume circuit includes resume routines executed by said microprocessor upon said microprocessor detecting a second System Management Mode interrupt to exit said reduced power consumption state;
wherein said microprocessor deasserts said first signal upon detecting said second System Management Mode interrupt to exit said reduced power consumption state; andwherein instructions in an instruction pipeline in said microprocessor are intercepted and stored prior to said microprocessor entering said reduced power consumption state. - View Dependent Claims (14, 15, 16, 17, 18, 19, 20)
-
Specification