US5311519A
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Multiplexer
Assignee: International Business Machines Corp
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Filing: 1992-04-20
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Granted: 1994-05-10
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Expires: 2012-04-20
Abstract
Abstract A multiplexer circuit which is built up from a series of smaller submultiplexers (241-247, 251-254). It selects a number of adjacent bits, bytes or words from one register and places them in the same order in a second register. The multiplexer can be used in cache memories or instruction buffers.
Inventors
- 👤 Klaus J. Getzlaff
- 👤 Thomas Pflueger
- 👤 Hans-Werner Tast
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 04:48
CPC Classifications
G; G06; G06F; G06F7/00; G06F7/76; G06F7/762; H; H04; H04J; H04J3/00; H04J3/02; H04J3/04; H04J3/047
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
169 words
Multiplexer for selecting m contiguous information units stored in m adjacent subsections of a first register containing n subsections and transferring said m information units to a second register containing m subsections, where m is less than n and n is greater than one, said multiplexer comprising: k logic stages which each contain z(x) submultiplexers compressing in the ratio q(x):1; wherein x is a variable from 1 to k; the first logic stage contains between n and m+(q(k)*q(k-1)* . . . *q(3)*q(2))-1 submultiplexers; the kth logic stage contains m submultiplexers; the xth logic stage contains between n and m+(q(k)*q(k-1)* . . . *q([k-]x+1))-1 submultiplexers for k>x>1; the outputs of the kth logic stage submultiplexers are connected to the inputs of the second register; the hth input to the ith submultiplexer in the xth logic stage is connected to the output of the i+(h-1)*(q(x+1)*q(x+2)* . . . *q(k))[-1] submultiplexer in the previous, (x-1)th, logic stage; and n is less than or equal to the product q(1)*q(2)* . . . *q(k-1)*q(k).
Claim 2
Dependent Claim
169 words
Multiplexer for selecting m contiguous information units stored in m adjacent subsections of a first register containing n subsections and transferring said m information units to a second register containing m subsections, where m is less than n and n is greater than one, said multiplexer comprising: k logic stages which each contain z(x) submultiplexers compressing in the ratio q(x):1; wherein x is a variable from 1 to k; the first logic stage contains between n and m+(q(k)*q(k-1)* . . . *q(3)*q(2))-1 submultiplexers; the kth logic stage contains m submultiplexers; the xth logic stage contains between n and m+(q(k)*q(k-1)* . . . *q([k-]x+1))-1 submultiplexers for k>x>1; the outputs of the kth logic stage submultiplexers are connected to the inputs of the second register; the hth input to the ith submultiplexer in the xth logic stage is connected to the output of the i+(h-1)*(q(x+1)*q(x+2)* . . . *q(k))[-1] submultiplexer in the previous, (x-1)th, logic stage; and n is less than or equal to the product q(1)*q(2)* . . . *q(k-1)*q(k).
Claim 3
Dependent Claim
62 words
Multiplexer according to claim 1 wherein each submultiplexer contains [q(k)]q(x) AND gates, the first inputs of which are connected to the output of one of the submultiplexers in the previous stage and the second input of which is connected to a multiplexer controller, and the output of which is connected to an OR gate whose output forms the output of the submultiplexer.
Claim 4
Dependent Claim
39 words
Multiplexer according to claim 1 wherein the first logic stage contains the smaller of n or m+(q(k)*q(k-1)* . . . *q(3)*q(2))-1 submultiplexers; and the xth logic stage contains the smaller of n or m+(q(k)*q(k-1)* . . . *q([k-]x+1))-1 submultiplexers.
Claim 5
Dependent Claim
17 words
Multiplexer according to claim 1 wherein the information units may be bits, bytes, half words or words.
Claim 6
Dependent Claim
32 words
Multiplexer according to claim 1 wherein the first register is an instruction buffer for storing a line of instructions and the second register is a buffer for holding the instruction being implemented.
Claim 7
Dependent Claim
9 words
Multiplexer according to claim 5 wherein m=2 and n=16.
Claim 8
Dependent Claim
24 words
Multiplexer according to claim 1 wherein the first register is a line of a cache memory; and the second register is a data buffer.
Claim 9
Dependent Claim
10 words
Multiplexer according to claim 7 in which m=8 and n=16.
Claim 10
Dependent Claim
10 words
Multiplexer according to claim 7 in which m=4 and n=16.
Claim 11
Dependent Claim
34 words
A multiplexer according to claim 1 wherein said logic stages select a number of adjacent bits, bytes or words from said first register and transfer them in the same order to said second register.
Claim 12
Dependent Claim
26 words
The multiplexer of claim 1 wherein the multiplexer forms a part of a cache memory for selecting the required data from a portion of the cache.
Claim 13
Dependent Claim
22 words
The multiplexer of claim 1 wherein the multiplexer forms a part of means for selecting the required instruction from an instruction buffer.
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) | 1997-05-09 | 1997-11-08 | 1998-05-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-05-09 | 2001-11-08 | 2002-05-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-05-09 | 2005-11-08 | 2006-05-10 | $7700.00 | Window Closed / Lapsed |