Asynchronous transceiver for on-vehicle electronic device

Abstract

An on-vehicle system comprises a Clock Extension Peripheral Interface (CXPI) bus and a device coupled to the CXPI bus as a slave node. The device comprises a transceiver configured to: generate a first signal by delaying an inverted signal of a transmission data signal: generate a second signal based on the transmission data signal, where the second signal has a low slew rate: selectively output the first signal or the second signal as a third signal, in response to a selector signal: and generate a clock signal in response to the third signal, where the clock signal is at a high level when the third signal is at a low level, and where the clock signal is at the low level when the third signal is at the high level.

1 . An on-vehicle electronic device comprising:
 a generating unit configured to generate a first clock for data communication with another on-vehicle electronic device through a Clock Extension Peripheral Interface (CXPI) communication network; and   an adjustment unit configured to adjust a duty width of the first clock to generate a second clock for the data communication with the other on-vehicle electronic device through the CXPI communication network.   
     
     
         2 . The on-vehicle electronic device according to  claim 1 , wherein
 the adjusting unit generates the second clock having a frequency higher than that of the first clock, and adjusts the duty width of the first clock at a ratio of a number of clocks of the second clock corresponding to a cycle of the first clock.   
     
     
         3 . The on-vehicle electronic device according to  claim 1 , wherein
 the adjusting unit adjusts the duty width of the first clock before encoding data to be transmitted through the CXPI communication network.   
     
     
         4 . The on-vehicle electronic device according to  claim 1 , wherein
 the adjusting unit adjusts the duty width of the first clock when transmitting encoded data through the CXPI communication network.   
     
     
         5 . The on-vehicle electronic device according to  claim 1 , which performs as a primary node of the CXPI communication network that provides the second clock as a reference clock to a bus of the CXPI communication network. 
     
     
         6 . The on-vehicle electronic device according to  claim 1 , further comprises:
 a micro controller unit (MCU); and   a transceiver coupled to the MCU coupled to the adjusting unit and a bus of the CXPI communication network, wherein the transceiver comprises:
 the generating unit comprising an internal clock generator; 
 an encoding/decoding unit; and 
 a waveform shaping unit coupled to the encoding/decoding unit. 
   
     
     
         7 . The on-vehicle electronic device according to  claim 6 , wherein the adjusting unit comprises:
 a first clock adjustment unit coupled to the internal clock generator, the MCU, and the encoding/decoding unit; and   a second clock adjustment unit coupled to the encoding/decoding unit and the bus.   
     
     
         8 . The on-vehicle electronic device according to  claim 6 , wherein the internal clock generator comprises a resistor and capacitor (RC) oscillator. 
     
     
         9 . The on-vehicle electronic device according to  claim 6 , wherein the adjustment unit is configured to:
 measure the duty width of the first clock received from the generating unit;   determine that the duty width is not a specified duty width;   adjust the duty width of the first clock to generate the second clock; and   output the second clock.   
     
     
         10 . The on-vehicle electronic device according to  claim 9 , further comprising:
 an encoding/decoding unit coupled to the adjustment unit, wherein the encoding/decoding unit is configured to encode data, using the second clock output from the adjustment unit to obtain encoded data; and   a waveform shaping unit coupled to the encoding/decoding unit, wherein the waveform shaping unit is configured to send the encoded data to a bus.   
     
     
         11 . The on-vehicle electronic device according to  claim 6 , wherein the adjustment unit is configured to:
 measure the duty width of the first clock received from the generating unit;   determine that the duty width is not a specified duty width;   adjust the duty width of the first clock by a first adjustment amount to generate the second clock;   measure the duty width of the second clock;   determine that the duty width is not the specified duty width;   adjust the duty width of the second clock by a second adjustment amount, wherein the second adjustment amount is less than the first adjustment amount; and   output the second clock.   
     
     
         12 . The on-vehicle electronic device according to  claim 11 , further comprising:
 an encoding/decoding unit coupled to the adjustment unit, wherein the encoding/decoding unit is configured to encode data, using the second clock output from the adjustment unit to obtain encoded data; and   a waveform shaping unit coupled to the encoding/decoding unit, wherein the waveform shaping unit is configured to send the encoded data to a bus.   
     
     
         13 . A method for clock generation in an on-vehicle electronic device, the method comprising:
 generating, by a generating unit of the on-vehicle electronic device, a first clock for data communication with another on-vehicle electronic device through a Clock Extension Peripheral Interface (CXPI) communication network; and   adjusting, by an adjustment unit of the on-vehicle electronic device, a duty width of the first clock to generate a second clock for the data communication with the other on-vehicle electronic device through the CXPI communication network.   
     
     
         14 . The method of  claim 13 , wherein adjusting the duty width comprises adjusting the duty width of the first clock at a ratio of a number of clocks of the second clock corresponding to a cycle of the first clock, the second clock having a frequency higher than that of the first clock. 
     
     
         15 . The method of  claim 13 , further comprising encoding data to be transmitted, wherein adjusting the duty width of the first clock occurs before the encoding. 
     
     
         16 . The method of  claim 13 , further comprising encoding data to be transmitted, wherein adjusting the duty width of the first clock after the encoding. 
     
     
         17 . An on-vehicle system comprising:
 a Clock Extension Peripheral Interface (CXPI) bus;   a first device coupled to the CXPI bus;   a second device coupled to the CXPI bus, wherein the first device comprises:
 a generating unit configured to generate a first clock for data communication with the second device through the CXPI bus; and 
 an adjustment unit configured to adjust a duty width of the first clock to generate a second clock for the data communication with the second device through the CXPI bus. 
   
     
     
         18 . The on-vehicle system according to  claim 17 , wherein the first device further comprises:
 a micro controller unit (MCU); and   a transceiver coupled to the MCU coupled to the adjusting unit and the CXPI bus, wherein the transceiver comprises:
 the generating unit comprising an internal clock generator; 
 an encoding/decoding unit; and 
 a waveform shaping unit coupled to the encoding/decoding unit. 
   
     
     
         19 . The on-vehicle system according to  claim 18 , wherein the adjusting unit comprises:
 a first clock adjustment unit coupled to the internal clock generator, the MCU, and the encoding/decoding unit; and   a second clock adjustment unit coupled to the encoding/decoding unit and the CXPI bus.   
     
     
         20 . The on-vehicle system according to  claim 17 , wherein the adjustment unit is configured to:
 measure the duty width of the first clock received from the generating unit;   determine that the duty width is not a specified duty width;   adjust the duty width of the first clock to generate the second clock; and   output the second clock.