Data processing apparatus

• US 6,385,714 B1
• Filed: 09/16/1998
• Issued: 05/07/2002
• Est. Priority Date: 09/18/1997
• Status: Expired due to Term

• Current Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Sanyo Electric Company Limited (Panasonic Holdings Corporation)
• Inventors: Matsumoto, Kenshi, Koumura, Yasuhito, Miura, Hiroki
• Primary Examiner(s): Pan, Daniel H.
• Application Number:
  US09/154,002
• Time in Patent Office: 1,329 Days
• Field of Search: 712/2, 712/3, 712/4, 712/5, 712/6, 712/13, 712/14, 712/16, 712/17, 712/18, 712/19, 712/23, 712/24, 712/26, 712/27, 712/32, 712/225, 712/34, 712/25, 712/245, 712/211, 712/210, 712/217, 712/230, 712/218, 712/219, 712/221, 712/41, 712/223, 711/214, 711/220, 710/29, 710/26, 708/490, 708/520
• US Class Current: 712/219
• CPC Class Codes: G06F 9/30098 Register arrangements
• CPC Class Codes: G06F 9/30123 according to context, e.g. thread buffers
• CPC Class Codes: G06F 9/3016 Decoding the operand specifier, e.g. specifier format

Abstract

A data processing apparatus uses a stored-program method to execute an operation instructed by an instruction word that includes a register designation code as an operand. A plurality of work registers are identifiable by register numbers, each of a typical number of bits. A correspondence table holds at least one of the register numbers in a state corresponding to register designation codes. The codes are stored in a readable condition, and have fewer bits than the register numbers. The data processing apparatus refers to the correspondence table when executing the operation.

Claims

1. A data processing apparatus using a stored-program method for executing an operation instructed by an instruction word including a register designation code as an operand, comprising:

a plurality of work registers identifiable by register numbers each of a typical number of bits; and

a correspondence table for holding at least one of the register numbers as designated register numbers in a state corresponding to register designation codes, wherein each of the register designation codes are in a readable condition and have few bits than the register number the correspondence table being referred to by the data processing apparatus when executing the operation.

2. A data processing apparatus according to claim 1, further comprising:

register number obtaining section for obtaining the designated register number from the correspondence table.

3. A data processing apparatus according to claim 2, further comprising:

designated register number storing section for storing the designated register number read from the correspondence table.

4. A data processing apparatus according to claim 3, further comprising:

designated register number returning section for returning the designated register number stored in the designated register number storing section back to the correspondence table.

5. A data processing apparatus according to claim 3 for executing specific processing, besides normal processing, in response to a process request supplied from either inside or outside thereof, further comprising:

designated register number updating section for updating the designated register number based on a predetermined rule according to the execution of an instruction word; and

correspondence table updating allowance/disallowance setting section for allowing or disallowing updating of the designated register number held in the correspondence table,

the designated register number storing section storing the designated register number in response to the acceptance of the request for the specific processing,

the correspondence table updating allowance/disallowance setting section disallowing updating of the designated register number held in the correspondence table in a period covering the process for storing the designated register number.

6. A data processing apparatus according to claim 4, wherein

the designated register number storing section is capable of saving a number of the designated register numbers read from the correspondence table, and

the designated register number returning section reads the number of the designated register numbers from the designated register number storing section in a reverse order in which the number of the designated register numbers were stored in the register number storing section, and returns them to the correspondence table.

7. A data processing apparatus according to claim 4 for executing specific processing, besides normal processing, in response to a process request supplied from either inside or outside thereof, further comprising:

designated register number updating section for updating the designated register number based on a predetermined rule according to the execution of an instruction word; and

correspondence table updating allowance/disallowance setting section for allowing or disallowing updating of the designated register number held in the correspondence table,

the designated register number storing section storing the designated register number in response to the acceptance of the request for the specific processing,

the correspondence table updating allowance/disallowance setting section disallowing updating of the designated register number held in the correspondence table in a period covering the process for storing the designated register number.

8. A data processing apparatus according to claim 4 for executing specific processing, besides normal processing, in response to a process request supplied from either inside or outside thereof, further comprising:

designated register number updating section for updating the designated register number based on a predetermined rule according to the execution of an instruction word; and

correspondence table updating allowance/disallowance setting section for allowing or disallowing updating of the designated register number held in the correspondence table,

the designated register number storing section storing the designated register number in response to the acceptance of the request for the specific processing,

the designated register number returning section returning the designated register number in response to the completion of the specific processing,

the correspondence table updating allowance/disallowance setting section disallowing updating of the designated register number held in the correspondence table in a period covering the process for storing the designated register number and the process for returning the designated register number back to the correspondence table.

9. A data processing apparatus according to claim 6 for executing specific processing, besides normal processing, in response to a process request supplied from either inside or outside thereof, further comprising:

designated register number updating section for updating the designated register numbers based on a predetermined rule according to the execution of an instruction word; and

correspondence table updating allowance/disallowance setting section for allowing or disallowing updating of the designated register numbers held in the correspondence table,

the designated register number storing section storing the designated register numbers in response to the acceptance of the request for the specific processing,

the correspondence table updating allowance/disallowance setting section disallowing updating of the designated register numbers held in the correspondence table in a period covering the process for storing the designated register numbers.

10. A data processing apparatus according to claim 6 for executing specific processing, besides normal processing, in response to a process request supplied from either inside or outside thereof, further comprising:

designated register number updating section for updating the designated register numbers based on a predetermined rule according to the execution of an instruction word; and

correspondence table updating allowance/disallowance setting section for allowing or disallowing updating of the designated register numbers held in the correspondence table,

the designated register number storing section storing the designated register numbers in response to the acceptance of the request for the specific processing,

the designated register number returning section returning the designated register numbers in response to the completion of the specific processing,

the correspondence table updating allowance/disallowance setting section disallowing updating of the designated register numbers held in the correspondence table in a period covering the process for storing the designated register numbers and the process for returning the designated register numbers back to the correspondence table.

11. A data processing apparatus according to claim 1, wherein the correspondence table holds a predetermined number of register numbers in instruction words preceding a current instruction word which were designated as destination registers for storing results of the operation and selected in an order of more recent designation.

12. A data processing apparatus according to claim 11, further comprising:

register number obtaining section for obtaining the designated register number from the correspondence table.

13. A data processing apparatus according to claim 12, further comprising:

designated register number storing section for storing the designated register number read from the correspondence table.

14. A data processing apparatus according to claim 13, further comprising:

designated register number returning section for returning the designated register number stored in the designated register number storing section back to the correspondence table.

15. A data processing apparatus according to claim 13 for executing specific processing, besides normal processing, in response to a process request supplied from either inside or outside thereof, further comprising:

designated register number updating section for updating the designated register number based on a predetermined rule according to the execution of an instruction word; and

correspondence table updating allowance/disallowance setting section for allowing or disallowing updating of the designated register number held in the correspondence table,

the designated register number storing section storing the designated register number in response to the acceptance of the request for the specific processing,

the correspondence table updating allowance/disallowance setting section disallowing updating of the designated register number held in the correspondence table in a period covering the process for storing the designated register number.

16. A data processing apparatus according to claim 14 for executing specific processing, besides normal processing, in response to a process request supplied from either inside or outside thereof, further comprising:

designated register number updating section for updating the designated register number based on a predetermined rule according to the execution of an instruction word; and

correspondence table updating allowance/disallowance setting section for allowing or disallowing updating of the designated register number held in the correspondence table,

the designated register number storing section storing the designated register number in response to the acceptance of the request for the specific processing,

the designated register number returning section returning the designated register number in response to the completion of the specific processing,

the correspondence table updating allowance/disallowance setting section disallowing updating of the designated register number held in the correspondence table in a period covering the process for storing the designated register number and the process for returning the designated register number back to the correspondence table.

17. A data processing apparatus according to claim 14, wherein;

the designated register number storing section is capable of saving a number of the designated register numbers read from the correspondence table, and

the designated register number returning section reads the number of the designated register numbers from the designated register number storing section in a reverse order in which the number of the designated register numbers were stored in the register number storing section, and returns them to the correspondence table.