US5138620A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Communication control system
Assignee: Hitachi Ltd
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Filing: 1991-06-07
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Granted: 1992-08-11
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Expires: 2011-06-07
Abstract
Abstract In a serial communication unit having a CRC calculator or in a single-chip micro-computer including the serial communication unit, the CRC calculator is operated in synchronism with a system clock which is different from and asynchronous with respect to a reception clock. As a result, the CRC calculation is prevented from being stopped by the interruption of the reception clock, or the CRC calculation by the software is unnecessitated, thereby improving the communication efficiency.
Inventors
- 👤 Takeshi Miyazaki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 07:28
CPC Classifications
H; H04; H04L; H04L1/00; H04L1/004; H04L1/0056; H04L1/0061; H03; H03M; H03M13/00; H03M13/03; H03M13/05; H03M13/09; H04L1/0057; H04L7/00; H04L7/04; H04L7/048
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
109 words
A single-chip microcomputer comprising: a calculator for calculating an error detection code of received data; latch circuits for storing the received data for a desired period of time; shift register means for converting the data stored in said latch circuits into serial data and for supplying the serial data to said calculator, wherein said shift register means and said calculator are operated in response to a clock signal which is asynchronous with respect to a reception clock synchronized with the received data; a counter for counting the reception clock so as to produce a calculation start signal for said calculator; and, a clock generator for providing said clock signal.
Claim 2
Dependent Claim
109 words
A single-chip microcomputer comprising: a calculator for calculating an error detection code of received data; latch circuits for storing the received data for a desired period of time; shift register means for converting the data stored in said latch circuits into serial data and for supplying the serial data to said calculator, wherein said shift register means and said calculator are operated in response to a clock signal which is asynchronous with respect to a reception clock synchronized with the received data; a counter for counting the reception clock so as to produce a calculation start signal for said calculator; and, a clock generator for providing said clock signal.
Claim 3
Dependent Claim
37 words
The single-chip microcomputer according to claim 1 further including a synchronization circuit adapted for connection with the reception clock for synchronizing the reception clock so as to fetch the received data in response to the synchronized clock.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-08-11 | 1996-02-10 | 1996-08-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-08-11 | 2000-02-10 | 2000-08-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-08-11 | 2004-02-10 | 2004-08-11 | $7700.00 | Window Closed / Lapsed |