Transceiver Timing Generator Synchronized to External Reference Clock
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Solution Overview
Problem
In on-vehicle communication systems, the accuracy of clock regeneration at nodes is degraded due to the use of oscillator circuits with lower frequency accuracy in transceivers, leading to errors in decoding processes and limited communication speed.
Innovation Solution
A transceiver configuration that generates a timing signal synchronized to an external reference clock, allowing for high-accuracy clock component transmission without internal clock errors, and includes a waveform shaping unit to perform waveform shaping based on the reference clock, ensuring accurate decoding and increased communication speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If an oscillator circuit with lower frequency accuracy is used in transceivers to reduce manufacturing cost, then manufacturing cost is reduced, but the accuracy of clock regeneration degrades
Solution Approach 1:
An external reference clock serves as an intermediary high-accuracy clock source. The transceiver receives this reference clock and uses it to generate the timing signal for encoding, thereby mediating between the low-accuracy internal oscillator and the high-accuracy clocking requirement, eliminating the need for high-accuracy oscillators in each transceiver while maintaining clock regeneration accuracy
Solution Approach 2:
The high-accuracy reference clock signal is copied and distributed to multiple transceivers. Each transceiver uses this copied reference clock signal to generate its timing signal, allowing all nodes to achieve high clock accuracy without each node requiring its own high-accuracy oscillator, thus reducing manufacturing cost while maintaining precision
2Device complexity
If the internal clock is used for encoding, then device complexity is reduced, but the accuracy of decoding process degrades due to clock error superposition
Solution Approach 1:
The internal clock function is extracted from the encoding process. Instead of using the internal clock for encoding, the invention extracts and uses an external reference clock for generating the timing signal, separating the low-accuracy internal clock from the high-precision timing requirement and eliminating error superposition in the decoding process
Solution Approach 2:
The external reference clock acts as an intermediary between the internal clock system and the encoding process. It provides a high-accuracy timing reference that mediates the encoding operation, preventing the degradation of decoding accuracy that would result from using the internal clock directly
3Productivity
If clock component extracted from received signal is used for synchronization, then communication speed can be maintained, but the accuracy of decoding process degrades
Solution Approach 1:
The reference clock is provided in advance to the transceiver before the actual data transmission and encoding process. This preliminary provision of a high-accuracy clock signal allows the transceiver to pre-synchronize its timing operations, ensuring both high communication speed and high decoding accuracy without relying on post-processing clock extraction
Data Source
AI summary
A transceiver that transmits and receives data used in a communication system, in which the data is encoded by a transmission line code and a signal level of the transmission code changes at a predetermined transition timing in a bit-duration. The transceiver includes: a clock generator that generates an internal clock used for internal circuits; a timing generator that generates, by using the internal clock generated by the clock generator, a timing signal synchronized to a reference clock supplied externally; an encoding circuit that encodes, by using the timing signal generated by the timing generator, a transmission data which is synchronized to the reference clock to be the transmission line code; and a waveform shaping unit that performs a waveform shaping of a waveform at the predetermined transition timing of the transmission data to be based on the reference clock.