# US 10,871,926 B2 · Information processing apparatus including SRAM capable of shifting to plurality of power saving modes according to control signal and control method thereof

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- Number: US 10,871,926 B2
- Document ID: US10871926B2
- Status: Granted
- Kind: B2
- Application number: 16/156,896
- Filed: 2018-10-10
- Published: 2019-04-18
- Granted: 2020-12-22
- Earliest claimed: 2017-10-18
- Assignees: Canon Kabushiki Kaisha
- Applicants: Canon Kabushiki Kaisha
- Inventors: Daisuke Matsunaga
- Web page: https://patentgrep.com/patent/US10871926B2

## CPC

- G06F 3/122: {with regard to computing resources, e.g. memory, CPU}
- G06F 1/32: Means for saving power
- G06F 1/3209: Monitoring remote activity, e.g. over telephone lines or network connections
- G06F 1/3228: Monitoring task completion, e.g. by use of idle timers, stop commands or wait commands
- G06F 1/3262: {Power saving in digitizer or tablet}
- G06F 1/3275: {Power saving in memory, e.g. RAM, cache}
- G06F 1/3284: {Power saving in printer}
- G06F 1/3287: by switching off individual functional units in the computer system
- G06F 3/1229: {Printer resources management or printer maintenance, e.g. device status, power levels}
- G06F 3/1259: {Print job monitoring, e.g. job status}
- H04N 1/00885: {Power supply means, e.g. arrangements for the control of power supply to the apparatus or components thereof}
- H04N 1/00896: {using a low-power mode, e.g. standby}
- H04N 1/00904: {Arrangements for supplying power to different circuits or for supplying power at different levels (H04N1/00896 takes precedence)}
- Y02D 10/00: Energy efficient computing, e.g. low power processors, power management or thermal management
- G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N)
- H04N: PICTORIAL COMMUNICATION, e.g. TELEVISION
- Y02D: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE

## Abstract

There is provided a control apparatus for controlling a static random access memory (SRAM) capable of shifting from a first power mode to a second power mode that is capable of holding data and saving more power than the first power mode or a third power mode that is not capable of holding data but is capable of saving more power than the second power mode. The control apparatus includes a first instruction unit configured to output an instruction for shifting the SRAM to the second power mode based on a state of the control apparatus and a second instruction unit configured to output an instruction for shifting the SRAM to the third power mode based on a state of the control apparatus.

## Claims

### Claim 1

A control apparatus comprising:
a controller configured to control a static random access memory (SRAM) capable of having a first power mode, a second power mode that is capable of holding data and saving power more than the first power mode, and a third power mode that is not capable of holding data but is capable of saving more power than the second power mode,
wherein the controller is configured to:
provide power to the SRAM to write image data into the SRAM;
write the image data into the powered SRAM while a power mode of the SRAM is the first power mode;
read the written image data from the powered SRAM while the power mode of the SRAM is the first power mode; and
shift the power mode of the powered SRAM from the first power mode to the third power mode based on a determination that all of the written image data has been read from the SRAM.

### Claim 2 (depends on 1)

The control apparatus according to claim 1, wherein the controller is further configured to detect data written in the SRAM.

### Claim 3 (depends on 2)

The control apparatus according to claim 2, wherein the controller is further configured to:
write data into the SRAM; and
read data from the SRAM,
wherein the controller detects data written in the SRAM and having not been read.

### Claim 4 (depends on 3)

The control apparatus according to claim 3, wherein, based on a write pointer indicating a writing position of data written and a read pointer indicating a reading position of data read, the controller detects data that has not been read from among data written in the SRAM.

### Claim 5 (depends on 4)

The control apparatus according to claim 4, wherein the controller detects that data that has not been read does not remain in the SRAM in a case where the write pointer and the read pointer indicate a same position, and detects that data that has not been read remains in the SRAM in a case where the write pointer and the read pointer indicate different positions.

### Claim 6 (depends on 4)

The control apparatus according to claim 4, wherein the write pointer is incremented when data is written, and the read pointer is incremented when data is read.

### Claim 7 (depends on 4)

The control apparatus according to claim 4, wherein the controller outputs an instruction for shifting the SRAM to the second power mode in a case where data that has not been read is stored in the SRAM, and the controller outputs an instruction for shifting the SRAM to the third power mode in a case where all of the data has been read fom the SRAM.

### Claim 8 (depends on 1)

The control apparatus according to claim 1, wherein the SRAM is a buffer.

### Claim 9 (depends on 7)

The control apparatus according to claim 7, wherein the controller is further configured to read an image,
wherein the controller outputs an instruction when the control apparatus is in a first power state in which the control apparatus can start reading a document, and
wherein the controller outputs the instruction when the control apparatus is in a second power state, with power consumption lower than that of the first power state in which the control apparatus cannot start reading a document.

### Claim 10 (depends on 1)

The control apparatus according to claim 1, wherein the read image data is transmitted to a next module.

### Claim 11

A control method of a static random access memory (SRAM) connected to a printing apparatus, capable of having a first power mode, a second power mode that is capable of holding data and save power more than the first power mode, and a third power mode that is not capable of holding data but is capable of saving more power than the second power mode, the control method comprising:
providing power to the SRAM to write image data into the SRAM;
writing the image data into the powered SRAM while a power mode of the SRAM is the first power mode,
reading the written image data from the powered SRAM while the power mode of the SRAM is the first power mode, and
shifting the power mode of the powered SRAM from the first power mode to the third power mode based on a determination that all of the written image data has been read from the SRAM.

### Claim 12

A control apparatus comprising:
a controller configured to control a static random access memory (SRAM) capable of having a first power mode, a second power mode that is capable of holding data and saving power more than the first power mode and a third power mode that is not capable of holding data but is capable of saving more power than the second power mode,
wherein the controller is configured to:
provide power to the SRAM to write image data into the SRAM and set the first power mode;
write the image data into the powered SRAM while a power mode of the SRAM is the first power mode;
read the written image data from the powered SRAM while the power mode of the SRAM is the first power mode; and
shift the power mode of the powered SRAM from the first power mode to the third power mode based on a determination that all of the written image data has been read from the SRAM.