EP0463775A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Multiple speed expansion card
Assignee: International Business Machines Corp
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Filing: 1991-06-14
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Granted: —
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Expires: 2011-06-14
Abstract
Abstract A timing circuit (18) for a multiple speed expansion card (14) generates a variable ready signal indicating when the expansion card can accept data enabling the expansion card to function in computer systems having different bus speeds. A controller circuit (12) of such a computer system exchanges information with the expansion card via a bus (16) at a speed related to the ready signal.
Inventors
- 👤 Howard Thomas Olnowich
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-08 08:25
CPC Classifications
G; G06; G06F; G06F13/00; G06F13/38; G06F13/42; G06F13/4204; G06F13/4208; G06F13/4217; G06F13/4221; G06F13/423
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
89 words
A computer system expansion card for connecting to a computer system bus (16), the expansion card comprising a timing circuit (18) for enabling the card (14) to transfer data to and from the bus (16), the timing circuit (18) comprising: a device control circuit (32) for generating a ready signal to indicate that the timing circuit (18) may transfer the data, characterised in that the data control circuit (32) varies the ready signal to indicate variations in the speed at which the timing circuit (18) can transfer the data.
Claim 2
Dependent Claim
52 words
An expansion card (14) as claimed in claim 1 wherein the timing circuit comprises a first speed selection circuit (26) for providing speed information based upon speed selection information received from the bus (16), the device control circuit (32) being configured to vary the ready signal in response to the speed information.
Claim 3
Dependent Claim
49 words
An expansion card (14) as claimed in claim 2 wherein the timing circuit comprises a first counter circuit (30) for providing a generate ready signal based upon the speed information, the device control circuit (32) being configured to vary the ready signal in response to the generate ready signal.
Claim 4
Dependent Claim
38 words
An expansion card (14) as claimed as claimed in claim 3 wherein the device control circuit (32) generates the ready signal in response to the generate ready signal and timing and control information received from the bus (16).
Claim 5
Dependent Claim
30 words
An expansion card (14) as claimed in claim 4 wherein the control information comprises a start transfer control signal indicating at what time to initiate transfer via the bus (16).
Claim 6
Dependent Claim
68 words
An expansion card (14) as claimed in claim 4 wherein the timing circuit comprises: a second speed selection circuit (24) for generating second speed selection information; and a second counter circuit (28) for generating a second generate ready signal; the device control circuit (32) being configured to receive the second generate ready signal and to generate the ready signal based upon selection information received from the bus (16).
Claim 7
Dependent Claim
26 words
An expansion card (14) as claimed in claim 6 wherein the selection information is based upon characteristics of the data information being transferred via the bus.
Claim 8
Dependent Claim
29 words
An expansion card (14) for connecting to a bus (16) of a computer system (10), the expansion card comprising a timing circuit (18) as claimed in any preceding claim.
Claim 9
Dependent Claim
80 words
A computer system (10) comprising: a bus (16); an expansion card (14) as claimed in any preceding claim; and a controller circuit (12) including a central processing unit (CPU) (12c), a system memory (12m) connected to the CPU (12c), and a bus control circuit connected to the CPU (12c) and the memory (12m) for controlling transfer of data the bus (16), the controller circuit (12) generating timing, speed selection, and control information to which the timing circuit (18) is responsive.
Claim 10
Dependent Claim
246 words
A timing circuit (18) for enabling a computer system expansion card (14) to data transfer to and from a computer system bus (16), the timing circuit comprising: a device control circuit (32) for generating a variable ready signal to indicate that the card (18) may transfer the data, the ready signal being varied by the device control circuit to indicate variations in the speed at which the timing circuit (18) can transfer the data; a first speed selection circuit (26) for providing speed information based upon speed selection information received from the bus (16), the device control circuit (32) being configured to vary the ready signal in response to the speed information; a first counter circuit (30) for providing a generate ready signal based upon the speed information, the device control circuit (32) being configured to vary the ready signal in response to the generate ready signal, and control information received from the bus (16), the control information comprising a start transfer control signal indicating at what time to initiate transfer via the bus (16); and a second speed selection circuit (24) for generating second speed selection information; and a second counter circuit (28) for generating a second generate ready signal; the device control circuit (32) being configured to receive the second generate ready signal and to generate the ready signal based upon selection information received from the bus (16), the selection information being based upon characteristics of the data information being transferred via the bus.
References Cited (Backward Citations)
No citation records indexed.
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