US5594873A
Expired / Lapsed
US
⏱️ 0.0 years remaining
System and method for identifying expansion devices in a computer system
Assignee: Dell USA LP
•
Filing: 1994-12-08
•
Granted: 1997-01-14
•
Expires: 2014-12-08
Abstract
Abstract A method and apparatus for identifying option modules or expansion devices coupled to an expansion bus using time domain methods. According to the present invention, each expansion device includes logic circuitry that asserts an identification signal a preset time duration after a host reset signal is pulsed. A unique preset time duration or time constant is designated for each expansion device, and the host computer identifies each expansion device by the length or duration of the identification signal. In the preferred embodiment, during the power-on sequence the computer system asserts a reset signal pulse to the identification logic in each respective expansion device which directs the expansion device to assert its identifying signal. The host computer determines the length of time between assertion of the reset signal pulse and assertion of the identification signal and uses this information to determine the type of expansion device.
Inventors
- 👤 James E. Garrett
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 19:09
CPC Classifications
G; G06; G06F; G06F9/00; G06F9/06; G06F9/44; G06F9/4401; G06F9/4411
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
74 words
A computer system having improved expansion device identification capabilities, comprising: a CPU; an expansion bus coupled to said CPU; at least one expansion device coupled to said expansion bus including identification logic which generates an identification signal having a predetermined time duration, wherein said predetermined time duration identifies said expansion device; and wherein said CPU receives said identification signal having said predetermined time duration and uses said identification signal to identify said expansion device.
Claim 2
Dependent Claim
74 words
A computer system having improved expansion device identification capabilities, comprising: a CPU; an expansion bus coupled to said CPU; at least one expansion device coupled to said expansion bus including identification logic which generates an identification signal having a predetermined time duration, wherein said predetermined time duration identifies said expansion device; and wherein said CPU receives said identification signal having said predetermined time duration and uses said identification signal to identify said expansion device.
Claim 3
Dependent Claim
43 words
The computer system of claim 1, wherein said CPU generates a reset signal pulse over said expansion bus to said expansion device; and wherein said identification logic generates said identification signal for said predetermined time duration after generation of said reset signal pulse.
Claim 4
Dependent Claim
20 words
The computer system of claim 2, wherein said computer system further comprises a timer which times said predetermined time duration.
Claim 5
Dependent Claim
31 words
The computer system of claim 2, wherein said identification logic negates said identification signal when said reset signal pulse is generated and asserts said identification signal after said predetermined time duration.
Claim 6
Dependent Claim
61 words
The computer system of claim 1, wherein said computer system further comprises a polling register which receives said identification signal; wherein said polling register includes one or more bits representing status of said identification signal; and wherein said CPU polls said one or more bits in said polling register to determine when said expansion device identification logic generates said identification signal.
Claim 7
Dependent Claim
17 words
The computer system of claim 1, wherein, said CPU includes an interrupt input receiving said identification signal.
Claim 8
Dependent Claim
23 words
The computer system of claim 1, wherein said identification logic includes a capacitor having a predetermined capacitance corresponding to said predetermined time duration.
Claim 9
Dependent Claim
24 words
The computer system of claim 7, wherein said predetermined time duration is set with an RC time constant using said capacitor and a resistor.
Claim 10
Dependent Claim
57 words
The computer system of claim 1, wherein said identification logic comprises a capacitor; wherein said computer system further comprises a gate having an input which is coupled to said capacitor when said expansion device is connected to said expansion bus; and wherein said gate generates said identification signal when said capacitor has charged to a predetermined voltage.
Claim 11
Dependent Claim
15 words
The computer system of claim 1, wherein said identification logic comprises a one shot timer.
Claim 12
Independent Claim
87 words
A method for identifying one or more expansion devices that are connected to an expansion bus in a computer system, comprising the steps of: providing power to the computer system; the expansion device generating an identification signal for a predetermined time, said step of generating occurring after said step of providing power to the computer system; the computer system determining said predetermined time that said identification signal was generated; and the computer system identifying the expansion device using said predetermined time determined in said step of determining.
Claim 13
Independent Claim
87 words
A method for identifying one or more expansion devices that are connected to an expansion bus in a computer system, comprising the steps of: providing power to the computer system; the expansion device generating an identification signal for a predetermined time, said step of generating occurring after said step of providing power to the computer system; the computer system determining said predetermined time that said identification signal was generated; and the computer system identifying the expansion device using said predetermined time determined in said step of determining.
Claim 14
Dependent Claim
58 words
The method of claim 11, further comprising: the computer system generating a signal to the expansion device after said step of providing power and prior to said step of generating said identification signal; wherein said step of generating said identification signal is performed immediately after said step of the computer system generating said signal to the identification logic.
Claim 15
Dependent Claim
29 words
The method of claim 12, wherein said step of the computer system generating said signal to the expansion device comprises generating a reset signal pulse to the expansion device.
Claim 16
Dependent Claim
50 words
The method of claim 11, wherein said step of the computer system determining said predetermined time that said identification signal was generated comprises: the computer system timing a duration of time that said identification signal is generated and storing a value indicative thereof and the computer system reading said value.
Claim 17
Dependent Claim
51 words
The method of claim 14, wherein said step of the computer system determining said predetermined time that said identification signal was generated further comprises: the computer system polling a register during said step of the computer system timing the duration of time to determine when said identification signal has been generated.
Claim 18
Dependent Claim
66 words
The method of claim 14, wherein said step of the computer system determining said predetermined time that said identification signal was generated further comprises: the computer system receiving said identification signal as an interrupt after said step of the computer system timing the duration of time; wherein said computer system performs said step of reading said value after said identification signal is received as an interrupt.
Claim 19
Dependent Claim
50 words
The method of claim 11, wherein said step of the expansion device generating said identification signal comprises: the expansion device negating said identification signal after said reset pulse signal is generated; and the expansion device asserting said identification signal at said predetermined time after said reset pulse signal is generated.
Claim 20
Dependent Claim
84 words
A computer system having improved expansion device identification capabilities, comprising: a CPU having an interrupt input; an expansion bus coupled to said CPU; at least one expansion device coupled to said expansion bus including identification logic which generates an identification signal having a predetermined time duration, wherein said predetermined time duration identifies said expansion device; and wherein said CPU receives said identification signal having said predetermined time duration at said interrupt input, and said CPU uses said identification signal to identify said expansion device.
Claim 21
Dependent Claim
84 words
A computer system having improved expansion device identification capabilities, comprising: a CPU having an interrupt input; an expansion bus coupled to said CPU; at least one expansion device coupled to said expansion bus including identification logic which generates an identification signal having a predetermined time duration, wherein said predetermined time duration identifies said expansion device; and wherein said CPU receives said identification signal having said predetermined time duration at said interrupt input, and said CPU uses said identification signal to identify said expansion device.
Claim 22
Dependent Claim
119 words
A computer system having improved expansion device identification capabilities, comprising: a CPU; an expansion bus coupled to said CPU; at least one expansion device coupled to said expansion bus including identification logic which generates an identification signal having a predetermined time duration, wherein said predetermined time duration identifies said expansion device and wherein said identification logic comprises a capacitor; a gate having an input which is coupled to said capacitor when said expansion device is connected to said expansion bus, wherein said gate generates said identification signal when said capacitor has charged to a predetermined voltage; and wherein said CPU receives said identification signal having said predetermined time duration and uses said identification signal to identify said expansion device.
Claim 23
Dependent Claim
119 words
A computer system having improved expansion device identification capabilities, comprising: a CPU; an expansion bus coupled to said CPU; at least one expansion device coupled to said expansion bus including identification logic which generates an identification signal having a predetermined time duration, wherein said predetermined time duration identifies said expansion device and wherein said identification logic comprises a capacitor; a gate having an input which is coupled to said capacitor when said expansion device is connected to said expansion bus, wherein said gate generates said identification signal when said capacitor has charged to a predetermined voltage; and wherein said CPU receives said identification signal having said predetermined time duration and uses said identification signal to identify said expansion device.
Claim 24
Independent Claim
134 words
A method for identifying one or more expansion devices that are connected to an expansion bus in a computer system, comprising the steps of: providing power to the computer system; the expansion device generating an identification signal for a predetermined time, said step of generating occurring after said step of providing power to the computer system; the computer system determining said predetermined time that said identification signal is generated, wherein the computer system determining said predetermined time comprises: the computer system beginning timing a duration of time when said identification signal is generated; the computer system receiving an interrupt after said predetermined time; and the computer system determining said duration of time after receiving said interrupt; and the computer system identifying the expansion device using said predetermined time determined in said step of determining.
Claim 25
Independent Claim
134 words
A method for identifying one or more expansion devices that are connected to an expansion bus in a computer system, comprising the steps of: providing power to the computer system; the expansion device generating an identification signal for a predetermined time, said step of generating occurring after said step of providing power to the computer system; the computer system determining said predetermined time that said identification signal is generated, wherein the computer system determining said predetermined time comprises: the computer system beginning timing a duration of time when said identification signal is generated; the computer system receiving an interrupt after said predetermined time; and the computer system determining said duration of time after receiving said interrupt; and the computer system identifying the expansion device using said predetermined time determined in said step of determining.
References Cited (Backward Citations)
US4775931A
Cited
US5140133A
Cited
US5465333A
Cited
US5319785A
Cited
US5359715A
Cited
US5297275A
Cited
US5491830A
Cited
US5454081A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2000-01-14 | 2000-07-15 | 2001-01-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2004-01-14 | 2004-07-15 | 2005-01-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2008-01-14 | 2008-07-15 | 2009-01-14 | $7700.00 | Window Closed / Lapsed |