US5751977A
Expired / Lapsed
US
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Wide SCSI bus controller with buffered acknowledge signal
Assignee: Hewlett Packard Development Co LP
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Filing: 1996-10-07
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Granted: 1998-05-12
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Expires: 2016-10-07
Abstract
Abstract SCSI controller circuitry for controlling devices on a wide SCSI bus that implement the wide SCSI bus standard according to SCSI-2 is implemented with improved circuitry for providing the wide SCSI bus acknowledge signal ACKB*. Specifically, a high speed analog buffer chip is provided that can sync and source over 55 milliamps, that has a propagation delay of 1.5 nanoseconds, and that follows its input with a high degree of accuracy. Using this circuitry, glitches are eliminated in devices with high lump capacitive loads and cross-talk on the wide SCSI bus.
Inventors
- 👤 Dennis J. Alexander
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 15:17
CPC Classifications
G; G06; G06F; G06F13/00; G06F13/38; G06F13/42; G06F13/4204; G06F13/4221; G06F13/4226
Claims Analysis
Total Claims: 36
Claim 1
Independent Claim
151 words
SCSI controller circuitry for controlling a wide SCSI device on a wide SCSI bus such as defined by the SCSI-2 specification working draft revision 10 L, the wide SCSI bus including an ACK* line, comprising: circuitry for providing and receiving signals used on the wide SCSI bus, said circuitry providing a SCSI acknowledge signal; and a fast buffer with an input and an output, said input receiving said SCSI acknowledge signal from said circuitry, said buffer providing a buffered SCSI ACK* signal to the ACK* line of the wide SCSI bus, and said fast buffer sourcing and sinking more than 55 milliamps into a capacitive load, wherein said fast buffer is of a non-saturating analog design, whereby said buffered SCSI ACK* signal tracks the SCSI acknowledge signal and whereby the slew rate of said buffered SCSI ACK* signal is a close approximation of the slew rate of said SCSI acknowledge signal.
Claim 2
Dependent Claim
151 words
SCSI controller circuitry for controlling a wide SCSI device on a wide SCSI bus such as defined by the SCSI-2 specification working draft revision 10 L, the wide SCSI bus including an ACK* line, comprising: circuitry for providing and receiving signals used on the wide SCSI bus, said circuitry providing a SCSI acknowledge signal; and a fast buffer with an input and an output, said input receiving said SCSI acknowledge signal from said circuitry, said buffer providing a buffered SCSI ACK* signal to the ACK* line of the wide SCSI bus, and said fast buffer sourcing and sinking more than 55 milliamps into a capacitive load, wherein said fast buffer is of a non-saturating analog design, whereby said buffered SCSI ACK* signal tracks the SCSI acknowledge signal and whereby the slew rate of said buffered SCSI ACK* signal is a close approximation of the slew rate of said SCSI acknowledge signal.
Claim 3
Dependent Claim
18 words
The SCSI controller circuitry of claim 1, wherein said fast buffer is a Micro Linear ML 65244 chip.
Claim 4
Dependent Claim
21 words
The SCSI controller circuitry of claim 1, wherein said fast buffer has a propagation delay of approximately 1.5 nanoseconds or less.
Claim 5
Dependent Claim
30 words
The SCSI controller circuitry of claim 1 further comprising a dampening resistor, and wherein said fast buffer provides said buffered SCSI ACK* signal to the ACK* line through said resistor.
Claim 6
Dependent Claim
16 words
The SCSI controller circuitry of claim 4, wherein said resistor has a value of 110 ohms.
Claim 7
Dependent Claim
52 words
The SCSI controller circuitry of claim 1 further comprising: a regulated 2.85 V supply; and a pull-up resistor tied to said regulated 2.85 V supply and to said SCSI acknowledge signal, whereby said SCSI acknowledge signal is pulled to 2.85 V when said SCSI acknowledge signal is left floating by said circuitry.
Claim 8
Dependent Claim
33 words
The SCSI controller circuitry of claim 1, wherein said SCSI acknowledge signal is the ACK* signal according to the SCSI-2 standard such as defined by the SCSI-2 specification working draft revision 10 L.
Claim 9
Dependent Claim
114 words
SCSI controller circuitry for controlling a wide SCSI device on a wide SCSI bus such as defined by the SCSI-2 specification working draft revision 10 L, the wide SCSI bus including an ACK* line, comprising: circuitry for providing and receiving signals used on the wide SCSI bus, said circuitry providing a SCSI acknowledge signal; and a fast buffer with an input and an output, said input receiving said SCSI acknowledge signal from said circuitry, said buffer providing a buffered SCSI ACK* signal to the ACK* line of the wide SCSI bus, and said fast buffer being provided at a location physically near the wide SCSI device relative to the length of the SCSI bus.
Claim 10
Dependent Claim
114 words
SCSI controller circuitry for controlling a wide SCSI device on a wide SCSI bus such as defined by the SCSI-2 specification working draft revision 10 L, the wide SCSI bus including an ACK* line, comprising: circuitry for providing and receiving signals used on the wide SCSI bus, said circuitry providing a SCSI acknowledge signal; and a fast buffer with an input and an output, said input receiving said SCSI acknowledge signal from said circuitry, said buffer providing a buffered SCSI ACK* signal to the ACK* line of the wide SCSI bus, and said fast buffer being provided at a location physically near the wide SCSI device relative to the length of the SCSI bus.
Claim 11
Dependent Claim
18 words
The SCSI controller circuitry of claim 8, wherein said fast buffer is a Micro Linear ML 65244 chip.
Claim 12
Dependent Claim
21 words
The SCSI controller circuitry of claim 8, wherein said fast buffer has a propagation delay of approximately 1.5 nanoseconds or less.
Claim 13
Dependent Claim
52 words
The SCSI controller circuitry of claim 8, wherein said fast buffer is of a non-saturating analog design, whereby said buffered SCSI ACK* signal tracks the SCSI acknowledge signal and whereby the slew rate of said buffered SCSI ACK* signal is a close approximation of the slew rate of said SCSI acknowledge signal.
Claim 14
Dependent Claim
30 words
The SCSI controller circuitry of claim 8 further comprising a dampening resistor, and wherein said fast buffer provides said buffered SCSI ACK* signal to the ACK* line through said resistor.
Claim 15
Dependent Claim
16 words
The SCSI controller circuitry of claim 12, wherein said resistor has a value of 110 ohms.
Claim 16
Dependent Claim
52 words
The SCSI controller circuitry of claim 8 further comprising: a regulated 2.85 V supply; and a pull-up resistor tied to said regulated 2.85 V supply and to said SCSI acknowledge signal, whereby said SCSI acknowledge signal is pulled to 2.85 V when said SCSI acknowledge signal is left floating by said circuitry.
Claim 17
Dependent Claim
33 words
The SCSI controller circuitry of claim 8, wherein said SCSI acknowledge signal is the ACK* signal according to the SCSI-2 standard such as defined by the SCSI-2 specification working draft revision 10 L.
Claim 18
Dependent Claim
22 words
The SCSI controller circuitry of claim 8, wherein said fast buffer sources and sinks more than 55 milliamps into a capacitive load.
Claim 19
Independent Claim
161 words
A system for providing data over a wide SCSI bus such as defined by the SCSI-2 specification working draft revision 10 L, the wide SCSI bus including an ACK* line, the system comprising: a peripheral mass storage device for providing data, the peripheral mass storage device having a second ACK* line; a connector for coupling to the wide SCSI bus; and a fast buffer with an input and an output, said input receiving a SCSI acknowledge signal from the ACK* line, said fast buffer providing a buffered SCSI ACK* signal to the second ACK* line of the peripheral mass storage device, and said fast buffer sourcing and sinking more than 55 milliamps into a capacitive load, wherein said fast buffer is of a non-saturating analog design, whereby said buffered SCSI ACK* signal tracks the SCSI acknowledge signal and whereby the slew rate of said buffered SCSI ACK* signal is a close approximation of the slew rate of said SCSI acknowledge signal.
Claim 20
Independent Claim
161 words
A system for providing data over a wide SCSI bus such as defined by the SCSI-2 specification working draft revision 10 L, the wide SCSI bus including an ACK* line, the system comprising: a peripheral mass storage device for providing data, the peripheral mass storage device having a second ACK* line; a connector for coupling to the wide SCSI bus; and a fast buffer with an input and an output, said input receiving a SCSI acknowledge signal from the ACK* line, said fast buffer providing a buffered SCSI ACK* signal to the second ACK* line of the peripheral mass storage device, and said fast buffer sourcing and sinking more than 55 milliamps into a capacitive load, wherein said fast buffer is of a non-saturating analog design, whereby said buffered SCSI ACK* signal tracks the SCSI acknowledge signal and whereby the slew rate of said buffered SCSI ACK* signal is a close approximation of the slew rate of said SCSI acknowledge signal.
Claim 21
Dependent Claim
16 words
The system of claim 17, wherein said fast buffer is a Micro Linear ML 65244 chip.
Claim 22
Dependent Claim
19 words
The system of claim 17, wherein said fast buffer has a propagation delay of approximately 1.5 nanoseconds or less.
Claim 23
Dependent Claim
29 words
The system of claim 17 further comprising a dampening resistor, and wherein said fast buffer provides said buffered SCSI ACK* signal to the second ACK* line through said resistor.
Claim 24
Dependent Claim
14 words
The system of claim 20, wherein said resistor has a value of 110 ohms.
Claim 25
Dependent Claim
50 words
The system of claim 17 further comprising: a regulated 2.85 V supply; and a pull-up resistor tied to said regulated 2.85 V supply and to said SCSI acknowledge signal, whereby said SCSI acknowledge signal is pulled to 2.85 V when said SCSI acknowledge signal is left floating by said circuitry.
Claim 26
Dependent Claim
31 words
The system of claim 17, wherein said SCSI acknowledge signal is the ACK* signal according to the SCSI-2 standard such as defined by the SCSI-2 specification working draft revision 10 L.
Claim 27
Independent Claim
124 words
A system for providing data over a wide SCSI bus such as defined by the SCSI-2 specification working draft revision 10 L, the wide SCSI bus including an ACK* line, the system comprising: a peripheral mass storage device for providing data, the peripheral mass storage device having a second ACK* line; a connector for coupling to the wide SCSI bus; and a fast buffer with an input and an output, said input receiving a SCSI acknowledge signal from the ACK* line, said fast buffer providing a buffered SCSI ACK* signal to the second ACK* line of the peripheral mass storage device, and said fast buffer being provided at a location physically near the wide SCSI device relative to the length of the SCSI bus.
Claim 28
Independent Claim
124 words
A system for providing data over a wide SCSI bus such as defined by the SCSI-2 specification working draft revision 10 L, the wide SCSI bus including an ACK* line, the system comprising: a peripheral mass storage device for providing data, the peripheral mass storage device having a second ACK* line; a connector for coupling to the wide SCSI bus; and a fast buffer with an input and an output, said input receiving a SCSI acknowledge signal from the ACK* line, said fast buffer providing a buffered SCSI ACK* signal to the second ACK* line of the peripheral mass storage device, and said fast buffer being provided at a location physically near the wide SCSI device relative to the length of the SCSI bus.
Claim 29
Dependent Claim
16 words
The system of claim 24, wherein said fast buffer is a Micro Linear ML 65244 chip.
Claim 30
Dependent Claim
19 words
The system of claim 24, wherein said fast buffer has a propagation delay of approximately 1.5 nanoseconds or less.
Claim 31
Dependent Claim
50 words
The system of claim 24, wherein said fast buffer is of a non-saturating analog design, whereby said buffered SCSI ACK* signal tracks the SCSI acknowledge signal and whereby the slew rate of said buffered SCSI ACK* signal is a close approximation of the slew rate of said SCSI acknowledge signal.
Claim 32
Dependent Claim
29 words
The system of claim 24 further comprising a dampening resistor, and wherein said fast buffer provides said buffered SCSI ACK* signal to the second ACK* line through said resistor.
Claim 33
Dependent Claim
14 words
The system of claim 28, wherein said resistor has a value of 110 ohms.
Claim 34
Dependent Claim
50 words
The system of claim 24 further comprising: a regulated 2.85 V supply; and a pull-up resistor tied to said regulated 2.85 V supply and to said SCSI acknowledge signal, whereby said SCSI acknowledge signal is pulled to 2.85 V when said SCSI acknowledge signal is left floating by said circuitry.
Claim 35
Dependent Claim
31 words
The system of claim 24, wherein said SCSI acknowledge signal is the ACK* signal according to the SCSI-2 standard such as defined by the SCSI-2 specification working draft revision 10 L.
Claim 36
Dependent Claim
20 words
The system of claim 24, wherein said fast buffer sources and sinks more than 55 milliamps into a capacitive load.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-05-11 | 2001-11-10 | 2002-05-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-05-11 | 2005-11-10 | 2006-05-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-05-11 | 2009-11-10 | 2010-05-12 | $7700.00 | Window Closed / Lapsed |