Data transfer control method and apparatus, and storage medium

• US 6,609,210 B1
• Filed: 12/10/1999
• Issued: 08/19/2003
• Est. Priority Date: 12/15/1998
• Status: Expired due to Fees

• Current Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Original Assignee: Canon Ayutthaya Limited (Canon Inc.)
• Inventors: Onuma, Nobuo
• Primary Examiner(s): Gaffin, Jeffrey
• Assistant Examiner(s): KIM, HAROLD J
• Application Number:
  US09/458,064
• Time in Patent Office: 1,348 Days
• Field of Search: 713/323, 713/324, 713/300, 710/15, 710/18, 710/33, 710/60
• US Class Current: 713/323
• CPC Class Codes: G06F 3/122 with regard to computing resources, e.g. memory, CPU
• CPC Class Codes: G06F 3/1229 Printer resources management or printer maintenance, e.g. device status, power levels
• CPC Class Codes: G06F 3/1236 Connection management
• CPC Class Codes: G06F 3/1284 Local printer device

Abstract

A data transfer control method for controlling data transfer between a host computer having a data generation processor and a data transfer processor, and a printer,

dynamically adjusts the sleep time requested of the low-order data transfer processor in accordance with the data reception capability of the printer.

Claims

1. A data transfer control method for controlling data transfer between a high-order data processing apparatus that includes a data generation processor and a data transfer processor, and a low-order data processing apparatus, said method comprising the steps of:

measuring a current elapsed time from a previous data transfer request to a current data transfer request;

comparing the current elapsed time measured in said measuring step with a previous elapsed time between two previous data transfer requests;

dynamically adjusting a sleep time by prolonging the sleep time when the current elapsed time is longer than the previous elapsed time, and by shortening the sleep time when the current elapsed time is shorter than the previous elapsed time; and

requesting an adjusted sleep time of the data transfer processor.

2. The method according to claim 1, wherein the high-order data processing apparatus is a host computer.

3. The method according to claim 1, wherein the low-order data processing apparatus is a printer.

4. The method according to claim 1, wherein, in said step of requesting an adjusted sleep time, the sleep time is prolonged or shortened by adding a first predetermined value to or subtracting a second predetermined value from a previous sleep time, respectively.

5. The method according to claim 1, further comprising the steps of:

calculating a unit transfer time required for transferring unit data by the data transfer processor;

comparing the unit transfer time with at least one threshold value; and

reducing the adjusted sleep time if the unit transfer time is not longer than the threshold value.

6. A data transfer control apparatus for controlling data transfer between a high-order processing apparatus that includes a data generation processor and data transfer processor, and a low-order data processing apparatus, said data transfer control apparatus comprising:

measurement means for measuring a current elapsed time from a previous data transfer request to a current data transfer request;

comparison means for comparing the current elapsed time measured by the measurement means with a previous elapsed time between two previous data transfer requests;

sleep time adjustment means for dynamically adjusting a sleep time by prolonging the sleep time when the current elapsed time is longer than the previous elapsed time, and by shortening the sleep time when the current elapsed time is shorter than the previous elapsed time; and

request means for requesting an adjusted sleep time of the data transfer processor.

7. The apparatus according to claim 6, wherein the high-order data processing apparatus is a host computer.

8. The apparatus according to claim 6, wherein the low-order data processing apparatus is a printer.

9. A data transfer control method for controlling data transfer between a high-order processing apparatus that includes a data generation processor and data transfer processor, and a low-order data processing apparatus, said method comprising:

a time measurement step of measuring a current elapsed time from a previous data transfer request to a current data transfer request;

a first comparison step of comparing the current elapsed time measured in said time measurement step with a previous elapsed time between two previous data transfer requests;

a sleep time adjustment step of determining that a processing load on the data generation processor has become heavier and prolonging a sleep time requested of the data transfer processor when the current elapsed time is longer than the previous elapsed time, and of determining that the processing load on the data generation processor has become lighter and shortening the sleep time requested of the data transfer processor when the current elapsed time is shorter than the previous elapsed time;

a time computation step of computing a required transfer time for transfer per byte, based on a total required time upon transferring a data block having an arbitrary number of bytes;

a second comparison step of comparing the required transfer time per byte with a number N of threshold values determined arbitrarily; and

an application step of applying a time obtained by dividing a required sleep time by the number N of threshold values prepared in advance when each threshold value condition is satisfied, as a result of a comparison in the second comparison step.

10. The method according to claim 9, wherein the high-order data processing apparatus is a host computer.

11. The method according to claim 9, wherein the low-order data processing apparatus is a printer.

12. A data transfer control apparatus for controlling data transfer between a high-order processing apparatus that includes a data generation processor and data transfer processor, and a low-order data processing apparatus, said data transfer control apparatus comprising:

time measurement means for measuring a current elapsed time from a previous data transfer request to a current data transfer request;

first comparison means for comparing the current elapsed time measured by said time measurement means with a previous elapsed time between two previous data transfer requests;

sleep time adjustment means for determining that a processing load on the high-order data generation processor has become heavier and prolonging a sleep time requested of the low-order data transfer processor when the current elapsed time is longer than the previous elapsed time, and for determining that the processing load on the high-order data generation processor has become lighter and shortening the sleep time requested of the low-order data transfer processor when the current elapsed time is shorter than the previous elapsed time;

time computation means for computing a required transfer time for transfer per byte, based on a total required time upon transferring a data block having an arbitrary number of bytes;

second comparison means for comparing the required transfer time per byte with a number N of threshold values determined arbitrarily; and

application means for applying a time obtained by dividing a required sleep time by the number N of threshold values prepared in advance when each threshold value condition is satisfied as a result of a comparison by said second comparison means.

13. The apparatus according to claim 12, wherein the high-order data processing apparatus is a host computer.

14. The apparatus according to claim 13, wherein the low-order data processing apparatus is a printer.

15. A storage medium storing a control program for implementing a method of controlling a data transfer control apparatus that controls data transfer between a high-order data processing apparatus, which includes a data generation processor and a transfer processor, and a low-order data processing apparatus, the method comprising the steps of:

measuring a current elapsed time from a previous data transfer request to a current data transfer request;

comparing the current elapsed time measured in said measuring step with a previous elapsed time between two previous data transfer requests;

dynamically adjusting a sleep time by prolonging the sleep time when the current elapsed time is longer than the previous elapsed time, and by shortening the sleep time when the current elapsed time is shorter than the previous elapsed time; and

requesting an adjusted sleep time of the data transfer processor.

16. The medium according to claim 15, wherein the high-order data processing apparatus is a host computer.

17. The medium according to claim 15, wherein the low-order data processing apparatus is a printer.

18. A storage medium storing a control program for implementing a method of controlling a data transfer control apparatus that controls data transfer between a high-order processing apparatus, which includes a data generation processor and a transfer processor, and a low-order data processing apparatus, the method comprising the steps of:

measuring a current elapsed time from a previous data transfer to a current data transfer;

comparing the measured current elapsed time with a previous elapsed time between two previous data transfer requests;

determining that a processing load on the data generation processor has become heavier and prolonging a sleep time requested of the data transfer processor when the current elapsed time is longer than the previous elapsed time, or determining that the processing load on the data generation processor has become lighter and shortening the sleep time requested of the data transfer processor when the current elapsed time is shorter than the previous elapsed time;

computing a required transfer time for transfer per byte, based on a total required time upon transferring a data block having an arbitrary number of bytes;

comparing the required transfer time per byte with a number N of threshold values determined arbitrarily; and

applying a time obtained by dividing a required sleep time by the number N of threshold values prepared in advance when each threshold value condition is satisfied as a result of a comparison.

19. The medium according to claim 18, wherein the high-order data processing apparatus is a host computer.

20. The medium according to claim 18, wherein the low-order data processing apparatus is a printer.