EP0364720A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Technique for implementing byte-wide UART transfers on a 16-bit data bus
Assignee: National Semiconductor Corp
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Filing: 1989-09-08
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Granted: —
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Expires: 2009-09-08
Abstract
Abstract A technique for transferring byte-wide serial data from a UART to a word-wide parallel data bus and vice versa is provided. Input control signals are established for the UART to specify the type of transfer to be implemented: odd byte, even byte or word. When a single byte is being sent from a CPU to a UART FIFO for serial transmission, then the predetermined storage location within the UART depends upon the address and the number of bytes being sent, not upon the byte's position on the data bus as is conventional. Similarly, when a serially received byte is to be transferred from a UART FIFO to the CPU, the next byte available is transferred to the data bus regardless of the position on the bus that it will occupy; in other words, regardless of whether it will be in the high byte or low byte position.
Inventors
- 👤 Martin S. Michael
- 👤 Franco Iacobelli
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 08:22
CPC Classifications
G; G06; G06F; G06F13/00; G06F13/38; G06F13/42; G06F13/40; G06F13/4004; G06F13/4009; G06F13/4018
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
98 words
A method of transferring serially-received byte-wide data from one of a plurality of data storage locations of a data communications device to a data processing system via a word-wide parallel data bus that comprises first-byte and second-byte positions, the method comprising: (a) retrieving data from the storage locations of the data communications device on a first-in-first-out basis; (b) placing byte-wide data retrieved from the next available storage location on the data bus regardless of whether the byte-wide data will occupy the first-byte position or the second-byte position; and (c) transferring the byte-wide data to the data processing system.
Claim 2
Independent Claim
98 words
A method of transferring serially-received byte-wide data from one of a plurality of data storage locations of a data communications device to a data processing system via a word-wide parallel data bus that comprises first-byte and second-byte positions, the method comprising: (a) retrieving data from the storage locations of the data communications device on a first-in-first-out basis; (b) placing byte-wide data retrieved from the next available storage location on the data bus regardless of whether the byte-wide data will occupy the first-byte position or the second-byte position; and (c) transferring the byte-wide data to the data processing system.
Claim 3
Independent Claim
105 words
An apparatus for transferring serially-received byte-wide data from one of a plurality of data storage locations of a data communications device to a data processing system via a word-wide parallel data bus that comprises first-byte and second-byte positions, the apparatus comprising: (a) means for retrieving data from the storage locations of the data communications device on a first-in-first-out basis; (b) means for placing the byte-wide data retrieved from the next available storage location on the data bus regardless of whether the byte-wide data will occupy the first-byte position or the second-byte position; and (c) means for transferring the byte-wide data to the data processing system.
Claim 4
Independent Claim
105 words
An apparatus for transferring serially-received byte-wide data from one of a plurality of data storage locations of a data communications device to a data processing system via a word-wide parallel data bus that comprises first-byte and second-byte positions, the apparatus comprising: (a) means for retrieving data from the storage locations of the data communications device on a first-in-first-out basis; (b) means for placing the byte-wide data retrieved from the next available storage location on the data bus regardless of whether the byte-wide data will occupy the first-byte position or the second-byte position; and (c) means for transferring the byte-wide data to the data processing system.
Claim 5
Independent Claim
98 words
A method of transferring byte-wide data from a word-wide parallel data bus of a data processing system, the data bus comprising first-byte and second-byte positions, to one of a plurality of storage locations of a data communications device for serial transfer to a peripheral system, the method comprising: (a) placing the byte-wide data on the data bus in a selected of the first-byte and second-byte positions; and (b) storing the byte-wide data in the next available storage location of the data communications device regardless of whether the data byte is in the first-byte position or the second-byte position.
Claim 6
Independent Claim
98 words
A method of transferring byte-wide data from a word-wide parallel data bus of a data processing system, the data bus comprising first-byte and second-byte positions, to one of a plurality of storage locations of a data communications device for serial transfer to a peripheral system, the method comprising: (a) placing the byte-wide data on the data bus in a selected of the first-byte and second-byte positions; and (b) storing the byte-wide data in the next available storage location of the data communications device regardless of whether the data byte is in the first-byte position or the second-byte position.
Claim 7
Dependent Claim
102 words
Apparatus for transferring byte-wide data from a word-wide parallel date bus of a data processing system, wherein the data bus comprises first-byte and second-byte positions, to one of a plurality of storage locations of a data communications device for serial transfer to a peripheral system, the apparatus comprising: (a) means for placing the byte-wide data on the data bus in a selected of the first-byte and second-byte positions; and (b) means for storing the byte-wide data in the next available storage location of the data communications device regardless of whether the byte-wide data is in the first-byte position or the second-byte position.
Claim 8
Dependent Claim
102 words
Apparatus for transferring byte-wide data from a word-wide parallel date bus of a data processing system, wherein the data bus comprises first-byte and second-byte positions, to one of a plurality of storage locations of a data communications device for serial transfer to a peripheral system, the apparatus comprising: (a) means for placing the byte-wide data on the data bus in a selected of the first-byte and second-byte positions; and (b) means for storing the byte-wide data in the next available storage location of the data communications device regardless of whether the byte-wide data is in the first-byte position or the second-byte position.
References Cited (Backward Citations)
US4514808A
Cited
EP0127007A2
Cited
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