US5140178A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Reset circuit for microcomputer
Assignee: Pioneer Corp
•
Filing: 1991-04-24
•
Granted: 1992-08-18
•
Expires: 2011-04-24
Abstract
Abstract In an electric apparatus which accommodates a built-in microcomputer which is supplied with power at all times regardless of a state of switching of a main power switch for an electric apparatus, a reset circuit for the microcomputer wherein a key-on monitor monitors a duration of keying of a reset key and derives a detected signal therefrom at the time when the key is depressed continuously over a predetermined threshold time, and a reset signal generator generates a reset signal based on a detected output of the key-on monitor and resets the microcomputer for initialization. According to this reset circuit, the built-in microcomputer can readily be reset without disconnecting the main power supply, that is different from the conventional apparatus wherein the reset is performed by detaching the attachment plug from the receptacle.
Inventors
- 👤 Masahiro Yoshihara
- 👤 Yoko Matsuzawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 17:58
CPC Classifications
H; H03; H03K; H03K17/00; H03K17/22; G; G06; G06F; G06F1/00; G06F1/24; H03K2017/226
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
99 words
In an electric apparatus containing a microcomputer wherein operating power is supplied to the microcomputer at all times regardless of main power supply to the electric apparatus, a reset circuit for the microcomputer comprising: key-on monitor means for monitoring a duration of key-on of a prescribed key, wherein said monitor means detects the operation of said key when depression thereof continues over a threshold time, and said monitor means produres an output upon such detection; and reset signal generator means for generating a reset signal based on the output of said key-on monitor means, and for resetting the microcomputer.
Claim 2
Dependent Claim
99 words
In an electric apparatus containing a microcomputer wherein operating power is supplied to the microcomputer at all times regardless of main power supply to the electric apparatus, a reset circuit for the microcomputer comprising: key-on monitor means for monitoring a duration of key-on of a prescribed key, wherein said monitor means detects the operation of said key when depression thereof continues over a threshold time, and said monitor means produres an output upon such detection; and reset signal generator means for generating a reset signal based on the output of said key-on monitor means, and for resetting the microcomputer.
Claim 3
Dependent Claim
19 words
A reset circuit for the microcomputer as defined in claim 1, wherein said key is an independent reset key.
Claim 4
Dependent Claim
20 words
A reset circuit for the microcomputer as defined in claim 1, wherein said key is incorporated with another operational key.
Claim 5
Dependent Claim
24 words
A reset circuit for the microcomputer as defined in claim 1, wherein said threshold time is determined by selecting a time constant for charging.
Claim 6
Dependent Claim
24 words
A reset circuit for the microcomputer as defined in claim 1, wherein said threshold time is determined by selecting a time constant for discharging.
Claim 7
Dependent Claim
56 words
A reset circuit for a microcomputer, comprising: (a) a monitor unit for producing an output signal in response to a key signal level held for a predetermined period of time; and (b) a reset signal generator, coupled to said monitor unit, said generator producing a reset signal to a microcomputer in response to said output signal.
Claim 8
Dependent Claim
56 words
A reset circuit for a microcomputer, comprising: (a) a monitor unit for producing an output signal in response to a key signal level held for a predetermined period of time; and (b) a reset signal generator, coupled to said monitor unit, said generator producing a reset signal to a microcomputer in response to said output signal.
Claim 9
Dependent Claim
18 words
The reset circuit of claim 6, further comprising: (c) a key manually operated to produce said key signal.
Claim 10
Dependent Claim
23 words
The reset circuit of claim 7, wherein said period of time is determined by selecting values of discrete components within said monitor unit.
References Cited (Backward Citations)
US4533837A
Cited
US4886983A
Cited
US4433390A
Cited
US4572966A
Cited
US4942311A
Cited
US4940909A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-08-18 | 1996-02-17 | 1996-08-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-08-18 | 2000-02-17 | 2000-08-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-08-18 | 2004-02-17 | 2004-08-18 | $7700.00 | Window Closed / Lapsed |