Low-power, standby mode computer
AssigneeGrid Systems Corporation
InventorsJames F. Cole, James H. McNamara
Life of this patent
Estimating the term…
Abstract
A method and apparatus for configuring a computer in a low-power mode are provided. In the low-power mode, dynamic random access memory is refreshed by a battery powered system in order to maintain the memory contents. Low-power mode is entered by saving an interrupt mask and by disabling interrupts, followed by saving the DMA status, finishing DMA operations, and disabling DMA. After these steps, the I/O state of the machine is saved by saving various I/O registers and ports. A refresh of the memory is forced before the system refresh operations are discontinued.
Claims30
Apparatus for preserving contents of refreshable dynamic memory in a data processor having a CPU, a programmable interrupt controller coupled to said CPU, a direct memory access controller, I/O state indicating registers coupled to said CPU, I/O ports coupled to said CPU, a dynamic random access memory coupled to said direct memory access controller and to said CPU, and a system controller chip having an unclocked sleep mode and an unpowered standby mode, the apparatus comprising:
- a first power system usable for powering said CPU and said controller chip and for powering refreshing of said memory;
- means, coupled to said CPU and said controller chip, for substantially discontinuing said powering of said CPU and said controller chip by said first power system to define a period of low-power consumption, said means for substantially discontinuing including;
- means for configuring said programmable interrupt controller, using said CPU, to disable acceptance of later interrupts;
- means for configuring said direct memory access controller, using said CPU, to disable later direct memory access operations wherein said configuring of said direct memory access controller occurs at a time following configuring of said programmable interrupt controller;
- means for saving, to said memory, the contents of at least some of said I/O state
- indicating registers and I/O ports, using said CPU, wherein said saving to said memory access at a time following configuring of said direct memory access controller;
- means for refreshing said memory, using said power system, during said period following said step of saving, to substantially preserve the contents of said memory, and
- means for initiating said standby mode of said system control chip using said CPU.
A data processor which can be configured to enter a low-power mode, said data processor including a CPU, a programmable interrupt controller coupled to said CPU, a direct memory access controller, I/O state indicating registers coupled to said CPU, I/O ports coupled to said CPU, a dynamic random access memory coupled to said direct memory access controller and to said CPU, and a system control chip coupled to said CPU having an unclocked sleep mode and an unpowered standby mode, the data processor being programmed to perform a process which includes:
- configuring said programmable interrupt controller, using said CPU, to disable acceptance of later interrupts;
- configuring said direct memory access controller, using said CPU, to disable later direct memory access operations wherein said configuring of said direct memory access controller occurs at a time following said step of configuring said programmable interrupt controller;
- saving, to said memory, the contents of at least some of said I/O state indicating registers and I/O ports, using said CPU, wherein said saving to said memory access at a time following said step of configuring said direct memory access controller;
- and
- refreshing said memory, using said CPU, wherein said refreshing of said memory occurs at a time following said step of saving.
A computer with power-saving apparatus comprising:
- a processing unit for processing user-input data in accordance with at least a first application program and outputting data generated during said execution of said application program;
- a memory, coupled to said processing unit;
- a user input device including a screen configured for receiving handwritten user input;
- first means for providing power to at least said processing unit and said user input device, said first means being configurable in a first configuration providing a first level of power and a second configuration providing a second level of power, said second level of power being less than said first level of power;
- and
- means for storing at least first data in said memory prior to configuring of said first means in said second configuration wherein said processing unit can use said first data to continue with execution of said application program, beginning with the configuration of said application program as of the time said first means was configured to said second configuration, substantially without loss of information input using said user input device prior to said configuring of said first means in said second configuration.
A portable, hand-held computer comprising:
- means for receiving handwritten user input data;
- means, coupled to said receiving means, for processing data in accordance with at least a first application program;
- memory storage means in communication with said means for processing data;
- power means for supplying power to said data receiving means and said processing means, said means for supplying power being switchable between a high power mode for supplying power at a high level and a low power mode for supplying power at a low level;
- means for storing at least first data in said memory, and for switching said means for supplying power to said low power mode at a first time during execution of said application program;
- means for retrieving said first data, switching said means for supplying power to said high power mode and continuing execution of said application program from the configuration said application program was in at said first time, substantially without loss of input, information, or programming which was input to said application program prior to said first time.
Dependencies are inferred from the claim text.