Portable remote terminal in which its clock frequency is switched

• US 5,909,585 A
• Filed: 09/17/1996
• Issued: 06/01/1999
• Est. Priority Date: 02/21/1996
• Status: Expired due to Fees

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Shinmiya, Kazumi
• Primary Examiner(s): Sheikh, Ayaz R.
• Assistant Examiner(s): PHAN, RAYMOND NGAN
• Application Number:
  US08/714,996
• Time in Patent Office: 987 Days
• Field of Search: 395/750, 395/282, 395/283, 395/556, 395/559, 395/733, 395/750.04, 395/750.08, 395/735, 395/740, 395/560
• US Class Current: 713/322
• CPC Class Codes: G06F 1/3228 Monitoring task completion, e.g. by use of idle timers, stop commands or wait commands

Abstract

A portable terminal comprising a state monitoring portion for monitoring an operating state of a microprocessor in a main control portion, and for increasing a clock frequency when the microprocessor conducts software processing in the main control portion, and for decreasing a clock frequency to supply the minimum operating clock for the microprocessor enough to operate when the microprocessor does not conducts the software processing. The present invention can save the power of the portable terminal effectively.

Claims

1. A portable terminal in which its clock frequency is switched, comprising:

a main controlling portion having a software processing portion using a microprocessor in said main controlling portion according to an interruption, said microprocessor including an operating system for driving software in said software processing portion and generating an interrupt signal,

a clock supply portion for supplying to said main controlling portion a clock signal which causes said microprocessor to operate, and

a state monitoring portion for monitoring, via the interrupt signal received from the operating system, an operating state of said software processing portion, wherein

said state monitoring portion sends a clock switching signal to said clock supply portion so that said clock supply portion sets a frequency of said clock signal to a high frequency when said software processing is being conducted and sets a frequency of said clock signal to a low frequency when said processing is not being conducted and

when no processing is conducted by said microprocessor for said software processing portion, the clock supply portion sets the clock frequency to a minimum, said minimum being below the operating frequency of the software processing portion but high enough for said state monitoring portion to operate.

2. The portable terminal according to claim 1 wherein said state monitoring portion changes said clock frequency up and down according to respective software operating load caused by said software processing portion.

3. The portable terminal according to claim 1 wherein said state monitoring portion shares a microprocessor with said software processing portion.

4. The portable terminal according to claim 1, wherein said minimum clock frequency is below 1 MHz.

5. The portable terminal according to claim 1, wherein said minimum clock frequency is 0.3 MHz.

6. The portable terminal according to claim 2 wherein said state monitoring portion shares a microprocessor with said software processing portion, and when no processing are conducted by said microprocessor for said software processing portion, the clock supply portion sets the minimum clock frequency which is enough for said state monitoring portion to operate.

7. A portable terminal in which its clock frequency is switched, comprising:

a main controlling portion having a software processing portion using a microprocessor in said main controlling portion according to an interruption, said microprocessor including an operating system for driving software in said software processing portion and generating an interrupt signal,

a clock supply portion for supplying to said main controlling portion a clock signal which causes said microprocessor to operate, and

a state monitoring portion for monitoring, via the interrupt signal received from the operating system, whether the microprocessor accesses an external memory, wherein

said state monitoring portion sends a clock switching signal to said clock supply portion so that said clock supply portion sets a frequency of said clock signal to a high frequency when the microprocessor accesses an external memory and sets a frequency of said clock signal to a low frequency when said microprocessor does not access the external memory and

when no memory accesses or software processing is conducted by said microprocessor for said software processing portion, the clock supply portion sets the clock frequency to a minimum, said minimum being below the operating frequency of the software processing portion but high enough for said state monitoring portion to operate.

8. The portable terminal according to claim 7 wherein said clock supply portion sets the minimum clock frequency which is enough for said state monitoring portion to operate, when the microprocessor does not access the external memory.

9. A power saving portable telephone having a communication state and a non-communication state comprising:

a main controlling portion having a software processing portion using a microprocessor in said main controlling portion according to an interruption, said microprocessor including an operating system for driving software in said software processing portion and generating an interrupt signal;

a clock supply portion for supplying to said main controlling portion a clock signal which causes said microprocessor to operate wherein said clock signal frequency is adjustable; and

a state monitoring portion for monitoring, via the interrupt signal received from the operating system, an operating state of said software processing portion, said state monitoring portion sends a clock switching signal to said clock supply portion so that said clock supply portion sets a frequency of said clock signal to high when said software processing is being conducted and sets a frequency of said clock signal to minimum when said processing is not being conducted, wherein

the setting of said clock frequency to high or minimum is independent of whether the telephone is in the communication state or non-communication state.

10. The portable telephone according to claim 9, wherein said minimum clock frequency is below 1 MHz.

11. The portable telephone according to claim 9, wherein said minimum clock frequency is 0.3 MHz.