EP0221303A2
Expired / Lapsed
EP
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Automatic I/O address assignment
Assignee: International Business Machines Corp
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Filing: 1986-09-16
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Granted: —
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Expires: 2006-09-16
Abstract
Abstract An automatic address assignment system (10) has a plurality of I/O devices (20,22,...M,28,30,...P(14) coupled to a bus. Each device contains a unique machine-readable identifier which is used to select the device for address assignment. The identifier is a binary bit string. Each bit position in the bit string is selected by the host in a serial manner with the host specifying which binary value is being solicited. All devices whose identifier digit matches the solicited value respond positively and remain in contention for address assignment. The other devices will not respond and drop out of contention for address assignment until the sequence is restarted from the first bit. After the bit sequence is completed, the address for that device is bused to the device, and the sequence is restarted from the first bit until all devices have been assigned an address.
Inventors
- 👤 David Elgar Aakre
- 👤 Douglas John Abrahamson
- 👤 Neil Clair Berglund
- 👤 Vincent Alfred Bettermann
- 👤 Lloyd Stephen Heim
- 👤 Kenneth Ardelle Moe
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-10 02:28
CPC Classifications
G; G06; G06F; G06F12/00; G06F12/02; G06F12/06; G06F12/0646; G06F12/0653; G06F12/0661
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
103 words
A method for automatically assigning addresses to a plurality of I/O devices communicatively coupled to a controller, each I/O device having a unique identifier and being capable of responding to communicated information as a function of the identifier, characterized in that it comprises the steps of: (a) communicating identification data from the controller to the I/O devices; (b) receiving responses from I/O devices having unique identifiers, at least a beginning portion of which matches the identification data received; and (c) assigning an address to an I/O device if said I/O device is the only I/O device which responded to the identification data transmitted.
Claim 2
Independent Claim
103 words
A method for automatically assigning addresses to a plurality of I/O devices communicatively coupled to a controller, each I/O device having a unique identifier and being capable of responding to communicated information as a function of the identifier, characterized in that it comprises the steps of: (a) communicating identification data from the controller to the I/O devices; (b) receiving responses from I/O devices having unique identifiers, at least a beginning portion of which matches the identification data received; and (c) assigning an address to an I/O device if said I/O device is the only I/O device which responded to the identification data transmitted.
Claim 3
Dependent Claim
31 words
The method of Claim 1 further characterized in that it comprises the step of: (d) starting at step (a) again with further identification data if more than one I/O device responded.
Claim 4
Dependent Claim
28 words
The method of Claim 2 characterized in that addresses are assigned to an I/O device when the identification data completely matches the unique identifier of an I/O device.
Claim 5
Dependent Claim
54 words
The method of Claim 2 characterized in that it further comprises the steps of: (e) determining if all I/O devices have been assigned an address; (f) starting at step (a) again, if all I/O devices do not have an assigned address; and (g) inhibiting devices from responding if said devices already have an address.
Claim 6
Independent Claim
37 words
The method of any one of Claims 1-4 characterized in that only one bit of identification data is transmitted in the first step (a), and only one bit of identification data is added in each step (d).
Claim 7
Dependent Claim
39 words
The method of Claim 5 characterized in that I/O devices which did not have identifiers matching each bit transmitted identification data drop out of contention for an address until the first bit position of identification data is transmitted again.
Claim 8
Dependent Claim
27 words
The method of Claim 4 characterized in that the unique identifier comprises a plurality of bits, and wherein the identification data also comprises a plurality of bits.
Claim 9
Dependent Claim
25 words
The method of Claim 1 characterized in that at least one I/O device first informs the controller that it does not have an address assigned.
Claim 10
Dependent Claim
20 words
The method of Claim 8 characterized in that I/O devices having an address assigned do not respond to identification data.
Claim 11
Dependent Claim
19 words
The method of Claim 1 characterized in that each I/O device has a non-volatile memory containing the unique identifier.
Claim 12
Dependent Claim
20 words
The method of Claim 10 characterized in that the unique identifier of each I/O device is 48 bits is length.
Claim 13
Dependent Claim
129 words
An automatic address assignment system having a plurality of I/O devices coupled to a bus, each I/O device having a unique identifier and being capable of responding to information on the bus as a function of the identifier, characterized in that it comprises: generator means coupled to the bus for selectively generating identification data in selected bit positions; response means within each I/O device for responding to the identification data generated by the generator means only when data in each bit position of the device's identifier corresponds to the identification data in corresponding bit positions; and address assignment means coupled to the generator means and to the response means for assigning addresses to I/O devices when such I/O devices are the only I/O devices responding to the identification data.
Claim 14
Dependent Claim
129 words
An automatic address assignment system having a plurality of I/O devices coupled to a bus, each I/O device having a unique identifier and being capable of responding to information on the bus as a function of the identifier, characterized in that it comprises: generator means coupled to the bus for selectively generating identification data in selected bit positions; response means within each I/O device for responding to the identification data generated by the generator means only when data in each bit position of the device's identifier corresponds to the identification data in corresponding bit positions; and address assignment means coupled to the generator means and to the response means for assigning addresses to I/O devices when such I/O devices are the only I/O devices responding to the identification data.
Claim 15
Dependent Claim
22 words
The automatic address assignment system of Claim 12 characterized in that each I/O device has a non-volatile memory containing a unique identifier.
Claim 16
Dependent Claim
34 words
The automatic address assignment system of Claim 12 characterized in that the response means does not respond to identification data after the response means has been assigned an address by the address assignment means.
Claim 17
Dependent Claim
29 words
The automatic address assignment system of Claim 13 characterized in that each I/O device further comprises an address register for storing the address assigned by the address assignment means.
Claim 18
Dependent Claim
29 words
The automatic address assignment system of Claim 15 characterized in that an I/O device which does not have an address assigned causes the generator means to generate identification data.
Claim 19
Dependent Claim
59 words
The automatic address assignment system of Claim 16 characterized in that the bus comprises a first mode of operation for conducting normal communications and a second mode of operation for automatic assignment of addresses, and wherein the second mode of operation uses the same connections as the first mode of operation without any physical changes to the bus means.
References Cited (Backward Citations)
No citation records indexed.
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