Method and system for processing using a CPU and digital signal processor

• US 6,981,134 B2
• Filed: 04/24/2002
• Issued: 12/27/2005
• Est. Priority Date: 04/24/2001
• Status: Expired due to Fees

• Current Assignee: Ricoh Company Limited
• Original Assignee: Ricoh Company Limited
• Inventors: Yamamura, Toshimi
• Primary Examiner(s): Cao, Chun
• Assistant Examiner(s): Bae, Ji H.
• Application Number:
  US10/128,366
• Publication Number:
  US 20030009656A1
• Time in Patent Office: 1,343 Days
• Field of Search: 381/61, 365/104, 711/136, 711/147, 711/209, 341/106, 341/155, 717/168, 712/217, 712/35, 713/1, 713/2, 713/100
• US Class Current: 713/1
• CPC Class Codes: G06F 15/177 Initialisation or configuration control processor initialisation G06F9/4405
• CPC Class Codes: G06F 9/4405 Initialisation of multiprocessor systems
• CPC Class Codes: G06F 9/445 Program loading or initiating bootstrapping G06F9/4401; security arrangements for program loading or initiating G06F21/57

Abstract

A processor processing method suitable for a processor system. The processor system comprises a CPU 10, a ROM 20 coupled to the CPU, and a DSP 30 having a memory unit 50 for storing programs and a processor unit 40 for processing data according to the programs. The ROM stores a plurality of programs and parameters required for processing the programs to the ROM. The CPU downloads an initial program to the memory unit of the DSP when a power is turned on. Then, the programs and the parameters corresponding to each process request from the system processor external are transferred from the ROM to the memory unit of the DSP. The data to be processed is input from the external of the processor system to the DSP; processing the data by the processor unit based on the programs and the parameters that are transferred to the memory unit, and then the processed data is output to the system processor external.

Claims

1. A method of processing with a processor system coupled to first and second external system processors, wherein the processor system comprises a CPU including a ROM, and a DSP having a memory unit for storing programs and a processor unit for processing data according to the programs, the method comprising the steps of:

storing a plurality of programs and a plurality of parameters in the ROM, at least one of said plurality of parameters used for processing at least one of the plurality of programs;

downloading an initial program from the CPU to the memory unit of the DSP when a power is turned on;

transferring a first program and a first parameter from the ROM to the memory unit of the DSP, said first program and first parameter corresponding to a first process request originating from the first external system processor;

inputting first data to the processor unit of the DSP from the first external system processor;

processing the first data by the processor unit of the DSP based on the first program and the first parameter;

outputting first processed data to a second external system processor;

transferring a second program and a second parameter corresponding from the ROM to the memory unit of the DSP, said second program and second parameter corresponding to a second process request originating from the first external system processor, said transferring a second program and a second parameter occurring without having to re-perform said downloading step;

inputting second data to the processor unit of the DSP from the first external system processor;

processing the second data by the processor unit of the DSP based on the second program and the second parameter; and

outputting second processed data to a second external system processor, said method further comprising;

holding a history of process requests by the CPU;

determining whether an incoming process request from the first external system processor is consistent with a past process request; and

performing at least one of

transferring a program and a parameter corresponding to said incoming process request from the ROM to the memory unit of the DSP if the incoming process request is not consistent with the past process request, and then processing corresponding incoming data; and

processing said corresponding incoming data with a program and a parameter that has previously been transferred to the memory unit of the DSP if the incoming process request is consistent with the past process request.

2. The method of claim 1, wherein:

said step of storing a plurality of programs and a plurality of parameters comprises storing in accordance with a type of process request, said method further comprising;

acquiring data corresponding to a plurality of input/output interfaces of the DSP, respectively; and

processing the acquired data by the processor unit.

3. The method of claim 2, further comprising:

preparing a table corresponding to the type of process request and a program group used for processing the type of process request; and

determining program groups and required parameters to be transferred to the DSP by the CPU by referring to the table.

4. The method of claim 3, wherein the table is stored in the ROM.

5. The method of claim 1, further comprising:

determining a memory use status of the memory unit of the DSP by the CPU;

locating an empty region in the memory unit; and

transferring one of said first program, said second programs, said first parameter, and second parameter from the ROM to the empty region in the memory unit.

6. The method of claim 1, further comprising

determining a memory use status of the memory unit of the DSP by the CPU;

and at least one of

locating an empty region in the memory unit, and then transferring said program and said parameter corresponding to said incoming process request from the ROM to the empty region in the memory unit; and

referring to the history of the process requests to instruct the DSP to release a region containing a program and a parameter not being used if said step of locating an empty region identifies there are no empty regions, and then transferring said program and said parameter corresponding to said incoming process request from the ROM to the released region.

7. The method of claim 1, further comprising:

detecting a memory use status of the memory unit of the DSP and a register use status of a register unit of the processor unit by the CPU;

wherein

at least one of said step of transferring a first program and a first parameter and said step of transferring a second program and a second parameter includes transferring to at least one of an empty region in the memory unit and an empty region in the register unit of the processor unit.

8. The method of claim 3, further comprising:

holding a history of process requests;

determining whether an incoming process request from the first external system processor is consistent with a past process request;

referring to said table and performing at least one of

transferring a program and a parameter corresponding to said incoming process request from the ROM to at least one of the memory unit and a register of the DSP if the incoming process request is not consistent with the past process request, and then processing corresponding incoming data; and

processing said corresponding incoming data with a program and a parameter that has previously been transferred to the memory unit of the DSP if the incoming process request is consistent with the past process request.

9. The method of claim 8, further comprising:

determining, by the CPU, a memory use status of the memory unit and a register use status of a register of the DSP; and

at least one of

locating an empty region in the memory unit and in the register, and then transferring said program and said parameter corresponding to said incoming process request from the ROM to the empty regions located in the memory unit and the register; and

referring to the history of the process requests to instruct the DSP to release a region in the memory unit and a region in the register where a program and a parameter is not being used if said step of locating an empty region identifies there are no empty regions in the memory unit and in the register, and then transferring at least one of said program and said parameter corresponding to said incoming process request from the ROM to the released regions in the memory unit and in the register.

10. The method of any one of claims 1, 7, 8 or 9, wherein the CPU holds the history if the past process requests one time.

11. The method of claim 7, wherein the register unit of the processor unit is connected to line memories, an image processing hardware, or an audio processing hardware.

12. The method of claim 6, wherein the transfer of the programs required from the CPU to the DSP is performed each time when the respective required program to process the process request is determined each time.

13. The method of claim 6, wherein the transfer of the programs required from the CPU to the DSP is performed once after the required program group to process the process request is determined.

14. A processor configured to be coupled to first and second external system processors, said processor comprising:

a CPU including a ROM; and

a DSP having a memory unit for storing programs and a processor unit for processing data according to the programs, wherein;

the CPU is configured

to store a plurality of programs and a plurality of parameters in the ROM, at least one of said plurality of parameters used for processing at least one of the plurality of programs;

to download an initial program to the memory unit of the DSP when a power is turned on;

to transfer a first program and a first parameter from the ROM to the memory unit of the DSP, said first program and first parameter corresponding to a first process request originating from the first external system processor;

to transfer, without having to download said initial program, a second program and a second parameter corresponding from the ROM to the memory unit of the DSP, said second program and second parameter corresponding to a second process request originating from the first external system processor; and

said DSP is configured to

input first data to the processor unit of the DSP from the first external system processor;

process the first data by the processor unit of the DSP based on the first program and the first parameter;

to output first processed data to a second external system processor;

to input second data to the processor unit of the DSP from the first external system processor;

to process the second data by the processor unit of the DSP based on the second program and the second parameter; and

to output second processed data to a second external system processor;

wherein said CPU is further configured to

hold a history of process requests by the CPU;

determine whether an incoming process request from the first external system processor is consistent with a past process request;

perform at least one of

transferring a program and a parameter corresponding to said incoming process request from the ROM to the memory unit of the DSP if the incoming process request is not consistent with the past process request, and then processing corresponding incoming data; and

processing said corresponding incoming data with a program and a parameter that has previously been transferred to the memory unit of the DSP if the incoming process request is consistent with the past process request.

15. The processor of claim 14, wherein said memory unit further comprises:

a RAM and a register.