Flex Ray: Coding and Decoding, Media Access Control, Frame and - - PowerPoint PPT Presentation

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Flex Ray: Coding and Decoding, Media Access Control, Frame and - - PowerPoint PPT Presentation

Aug 16, 2023 362 likes •1.01k views

Flex Ray: Coding and Decoding, Media Access Control, Frame and Symbol Processing Seminar: The FlexRay Communication Protocol Chair of Prof. Dr. W. J. Paul Talk by Michael Gerke 27-9-2005 Overview Media access Frame and control (MAC)

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SLIDE 1

Flex Ray: Coding and Decoding, Media Access Control, Frame and Symbol Processing

Seminar: The FlexRay Communication Protocol Chair of Prof. Dr. W. J. Paul Talk by Michael Gerke 27-9-2005

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SLIDE 2

Overview

Coding and decoding (CODEC) Media access control (MAC) Frame and symbol processing (FSP)

Bus

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SLIDE 3

Media access control (MAC)

  • Interface:

from Controller host interface (Host) to Coding and decoding (CODEC)

  • Controls timing
  • Orders ENC to sent symbols
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SLIDE 4

Media access control (MAC)

  • Controls access to the channels
  • Guarantees compliance with schedule

time organization Static segment Dynamic segment Symbol window Network idle time static slot static slot Communication cycle

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SLIDE 5

Media access control (MAC)

Static slot usage:

  • short idle time
  • transfer of the frame
  • long idle time
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SLIDE 6

Media access control (MAC)

Assembles frames:

  • imports data from controller host interface

(Host)

  • assembles header
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SLIDE 7

Coding and Decoding

Bit strobing Encoding Decoding Wakeup symbol decoding Channel idle Bus

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SLIDE 8

Encoding (ENC)

Frames

Frame coding in static segment 1

Transmission start sequence

TSS

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SLIDE 9

Encoding (ENC)

Frames

Frame coding in static segment 1

Transmission start sequence

TSS

Frame start sequence

FSS

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SLIDE 10

Encoding (ENC)

Frames

Frame coding in static segment 1

Transmission start sequence

TSS

Frame start sequence

FSS

Byte start sequence

BSS

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SLIDE 11

Encoding (ENC)

Frames

Frame coding in static segment Byte 1

Transmission start sequence

TSS

Frame start sequence

FSS

Byte start sequence

BSS

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SLIDE 12

Encoding (ENC)

Frames

Frame coding in static segment Byte 1

Transmission start sequence

TSS

Frame start sequence

FSS

Byte start sequence

BSS

Byte start sequence

BSS

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SLIDE 13

Encoding (ENC)

Frames

Frame coding in static segment Byte 1

Transmission start sequence

TSS

Frame start sequence

FSS

Byte start sequence

BSS

Byte start sequence

BSS Byte

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SLIDE 14

Encoding (ENC)

Frames

Frame coding in static segment Byte 1

Transmission start sequence

TSS

Frame start sequence

FSS

Byte start sequence

BSS

Byte start sequence

BSS Byte

Frame end sequence

FES

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SLIDE 15

Encoding (ENC)

Frames

Frame coding in static segment Byte 1

Transmission start sequence

TSS

Frame start sequence

FSS

Byte start sequence

BSS

Byte start sequence

BSS Byte

Frame end sequence

FES

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SLIDE 16

Encoding (ENC)

Symbols Collision avoidance and media access test symbol (CAS/MTS): TSS+030 Wakeup symbol (WUS): 015-60+idle45-180 sent in a wakeup pattern (WUP): WUS2-63

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SLIDE 17

Bit strobing (BITSTRB)

  • Takes 8 samples of every bit
  • Majority voting over last 5 bit samples
  • Selects 1 sample out of 8
  • Low level synchronization
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SLIDE 18

Bit strobing: Majority voting

Majority voting over last 5 bit samples

1 11111 voting window 1 voted value 1 voted value from BUS

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SLIDE 19

11110 voting window 1 voted value

Majority voting over last 5 bit samples

Bit strobing: Majority voting

1 1 voted value from BUS

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SLIDE 20

11100 voting window 1 voted value

Majority voting over last 5 bit samples

Bit strobing: Majority voting

1 1 voted value from BUS

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SLIDE 21

11000 voting window voted value

Majority voting over last 5 bit samples

Bit strobing: Majority voting

1 1 voted value from BUS

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SLIDE 22

11000 voting window voted value

Majority voting over last 5 bit samples

Bit strobing: Majority voting

Voting delay 1 1 voted value from BUS

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SLIDE 23

10000 voting window voted value

Majority voting over last 5 bit samples

Bit strobing: Majority voting

1 1 voted value from BUS

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SLIDE 24

00000 voting window voted value

Majority voting over last 5 bit samples

Bit strobing: Majority voting

1 1 voted value from BUS

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SLIDE 25

00001 voting window voted value

Majority voting over last 5 bit samples

glitch

Bit strobing: Majority voting

1 1 voted value from BUS

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SLIDE 26

00010 voting window voted value

Majority voting over last 5 bit samples

Bit strobing: Majority voting

glitch 1 1 voted value from BUS

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SLIDE 27

00100 voting window voted value

Majority voting over last 5 bit samples

Bit strobing: Majority voting

glitch 1 1 voted value from BUS

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SLIDE 28

01000 voting window voted value

Majority voting over last 5 bit samples

Bit strobing: Majority voting

glitch 1 1 voted value from BUS

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SLIDE 29

10001 voting window voted value

Majority voting over last 5 bit samples

Bit strobing: Majority voting

glitch 1 1 voted value from BUS

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SLIDE 30

00011 voting window voted value

Majority voting over last 5 bit samples

Bit strobing: Majority voting

1 1 voted value from BUS

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SLIDE 31

00111 voting window 1 voted value

Majority voting over last 5 bit samples

Bit strobing: Majority voting

1 1 voted value from BUS

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SLIDE 32

01111 voting window 1 voted value

Majority voting over last 5 bit samples

Bit strobing: Majority voting

1 1 voted value from BUS

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SLIDE 33

11111 voting window 1 voted value

Majority voting over last 5 bit samples

Bit strobing: Majority voting

1 1 voted value from BUS

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SLIDE 34

Bit strobing: Strobing

  • Every 5th sample out of the 8 samples „strobed“
  • Low-level synchronization of strobecounter in BSS

1 voted value

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SLIDE 35
  • Every 5th sample out of the 8 samples „strobed“
  • Low-level synchronization of strobecounter in BSS

1 voted value Strobecounter : 1 1

Bit strobing: Strobing

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SLIDE 36
  • Every 5th sample out of the 8 samples „strobed“
  • Low-level synchronization of strobecounter in BSS

voted value Strobecounter : 2 1 2

Bit strobing: Strobing

1

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SLIDE 37
  • Every 5th sample out of the 8 samples „strobed“
  • Low-level synchronization of strobecounter in BSS

voted value Strobecounter : 3 1 2 3

Bit strobing: Strobing

1

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SLIDE 38
  • Every 5th sample out of the 8 samples „strobed“
  • Low-level synchronization of strobecounter in BSS

voted value Strobecounter : 4 1 2 3 4

Bit strobing: Strobing

1

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SLIDE 39
  • Every 5th sample out of the 8 samples „strobed“
  • Low-level synchronization of strobecounter in BSS

voted value Strobecounter : 5 1 2 3 4 5

Bit strobing: Strobing

1

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SLIDE 40
  • Every 5th sample out of the 8 samples „strobed“
  • Low-level synchronization of strobecounter in BSS

voted value Strobecounter : 5 1 2 3 4 5 Bit strobed: 0

Bit strobing: Strobing

1

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SLIDE 41
  • Every 5th sample out of the 8 samples „strobed“
  • Low-level synchronization of strobecounter in BSS

voted value Strobecounter : 6 1 2 3 4 5 6

Bit strobing: Strobing

1

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SLIDE 42
  • Every 5th sample out of the 8 samples „strobed“
  • Low-level synchronization of strobecounter in BSS

voted value Strobecounter : 7 1 2 3 4 5 6 7

Bit strobing: Strobing

1

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SLIDE 43
  • Every 5th sample out of the 8 samples „strobed“
  • Low-level synchronization of strobecounter in BSS

voted value Strobecounter : 8 1 2 3 4 5 6 7 8

Bit strobing: Strobing

1

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SLIDE 44
  • Every 5th sample out of the 8 samples „strobed“
  • Low-level synchronization of strobecounter in BSS

voted value Strobecounter : 1 1 2 3 4 5 6 7 8 1

Bit strobing: Strobing

1

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SLIDE 45
  • Every 5th sample out of the 8 samples „strobed“
  • Low-level synchronization of strobecounter in BSS

voted value Strobecounter : 1 1 2 3 4 5 6 7 BSS 8 1

Bit strobing: Synchronization

1

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SLIDE 46

Bit strobing: Synchronization

  • Every 5th sample out of the 8 samples „strobed“
  • Low-level synchronization of strobecounter in BSS

voted value Strobecounter : 2 1 2 3 4 5 6 7 BSS 8 1 2 1

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SLIDE 47

Bit strobing: Synchronization

  • Every 5th sample out of the 8 samples „strobed“
  • Low-level synchronization of strobecounter in BSS

voted value Strobecounter : 3 1 2 3 4 5 6 7 BSS 8 1 2 3 1

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SLIDE 48

Bit strobing: Synchronization

  • Every 5th sample out of the 8 samples „strobed“
  • Low-level synchronization of strobecounter in BSS

voted value Strobecounter : 4 1 2 3 4 5 6 7 BSS 8 1 2 3 4 1

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SLIDE 49

Bit strobing: Synchronization

  • Every 5th sample out of the 8 samples „strobed“
  • Low-level synchronization of strobecounter in BSS

voted value Strobecounter : 5 1 2 3 4 5 6 7 BSS 8 1 2 3 4 5 1

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SLIDE 50

Bit strobing: Synchronization

  • Every 5th sample out of the 8 samples „strobed“
  • Low-level synchronization of strobecounter in BSS

voted value Strobecounter : 6 1 2 3 4 5 6 7 BSS 8 1 2 3 4 5 6 1

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SLIDE 51

Bit strobing: Synchronization

  • Every 5th sample out of the 8 samples „strobed“
  • Low-level synchronization of strobecounter in BSS

voted value Strobecounter : 1 1 2 3 4 5 6 7 BSS 8 1 2 3 4 5 6 1 sync edge 1

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SLIDE 52

Bit strobing: Synchronization

  • Every 5th sample out of the 8 samples „strobed“
  • Low-level synchronization of strobecounter in BSS

voted value Strobecounter : 2 1 2 3 4 5 6 7 BSS 8 1 2 3 4 5 6 1 sync edge 2 1

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SLIDE 53

Bit strobing: Synchronization

  • Every 5th sample out of the 8 samples „strobed“
  • Low-level synchronization of strobecounter in BSS

voted value Strobecounter : 3 1 2 3 4 5 6 7 BSS 8 1 2 3 4 5 6 1 sync edge 2 3 1

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SLIDE 54

Bit strobing: Synchronization

  • Every 5th sample out of the 8 samples „strobed“
  • Low-level synchronization of strobecounter in BSS

voted value Strobecounter : 4 1 2 3 4 5 6 7 BSS 8 1 2 3 4 5 6 1 sync edge 2 3 4 1

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SLIDE 55

Bit strobing: Synchronization

  • Every 5th sample out of the 8 samples „strobed“
  • Low-level synchronization of strobecounter in BSS

voted value Strobecounter : 5 1 2 3 4 5 6 7 BSS 8 1 2 3 4 5 6 1 sync edge 2 3 4 5 1

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SLIDE 56

Bit strobing: Synchronization

  • Every 5th sample out of the 8 samples „strobed“
  • Low-level synchronization of strobecounter in BSS

voted value Strobecounter : 6 1 2 3 4 5 6 7 BSS 8 1 2 3 4 5 6 1 sync edge 2 3 4 5 6 1

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SLIDE 57

Bit strobing: Synchronization

  • Every 5th sample out of the 8 samples „strobed“
  • Low-level synchronization of strobecounter in BSS

voted value Strobecounter : 7 1 2 3 4 5 6 7 BSS 8 1 2 3 4 5 6 1 sync edge 2 3 4 5 6 7 1

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SLIDE 58

Bit strobing: Synchronization

  • Every 5th sample out of the 8 samples „strobed“
  • Low-level synchronization of strobecounter in BSS

voted value Strobecounter : 8 1 2 3 4 5 6 7 BSS 8 1 2 3 4 5 6 1 sync edge 2 3 4 5 6 7 8 1

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SLIDE 59

Bit strobing: Synchronization

  • Every 5th sample out of the 8 samples „strobed“
  • Low-level synchronization of strobecounter in BSS

voted value Strobecounter : 1 1 2 3 4 5 6 7 BSS 8 1 2 3 4 5 6 1 sync edge 2 3 4 5 6 7 8 1 start of byte 1

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SLIDE 60

Wakeup symbol decoding (WUSDEC)

  • Waits for a WUP like pattern:

0x+1y+0x produced by two consecutive WUS

  • Reports to protocol operation control(POC)
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SLIDE 61

Channel idle (IDET)

Whenever 111 is received, a channel idle recognition point (CHIRP) is reported.

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SLIDE 62

Decoding (DEC)

  • Handles reception of CAS/MTS and frames
  • Interface from BITSTRB to FSP and POC
  • Checks for errors

Frames:

  • reassembles the message
  • checks format
  • checks CRC (frame “fingerprint”)

CAS/MTS:

  • checks length of

LOW signal

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SLIDE 63

Frame and symbol processing (FSP)

  • Interface from DEC to Host
  • Controls integrity of communication:
  • Checks for appropriate segment
  • Checks length of communication elements
  • Checks for correct header
  • Reports errors
  • Dismantles frame and passes on the payload
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SLIDE 64

Questions?

Coding and decoding (CODEC) Media access control (MAC) Frame and symbol processing (FSP)

Bus