23
2012/2/4 1 Coder and Decoder in NFC Device

Coder and Decoder in NFC Device - homepage.fudan.edu.cnhomepage.fudan.edu.cn/...and-Decoder-in-NFC-Device.pdf · Coder and Decoder in NFC Device ... Anti-Collision in decoder 0 1

  • Upload
    vuthu

  • View
    244

  • Download
    0

Embed Size (px)

Citation preview

Page 1: Coder and Decoder in NFC Device - homepage.fudan.edu.cnhomepage.fudan.edu.cn/...and-Decoder-in-NFC-Device.pdf · Coder and Decoder in NFC Device ... Anti-Collision in decoder 0 1

2012/2/4 1

Coder and Decoder in NFC Device

王 心

Page 2: Coder and Decoder in NFC Device - homepage.fudan.edu.cnhomepage.fudan.edu.cn/...and-Decoder-in-NFC-Device.pdf · Coder and Decoder in NFC Device ... Anti-Collision in decoder 0 1

2012/2/4 2

Agenda

Overview Frame structure Design detail (problem and solution) Simulation result Conclusion

Page 3: Coder and Decoder in NFC Device - homepage.fudan.edu.cnhomepage.fudan.edu.cn/...and-Decoder-in-NFC-Device.pdf · Coder and Decoder in NFC Device ... Anti-Collision in decoder 0 1

2012/2/4 3

Agenda

Overview Frame structure Design detail (problem and solution) Simulation result Conclusion

Page 4: Coder and Decoder in NFC Device - homepage.fudan.edu.cnhomepage.fudan.edu.cn/...and-Decoder-in-NFC-Device.pdf · Coder and Decoder in NFC Device ... Anti-Collision in decoder 0 1

2012/2/4 4

overview

CU

Decoder

DECMUXCRC

FIFO

Coder

CGM

PWM

CMP

RDM

Page 5: Coder and Decoder in NFC Device - homepage.fudan.edu.cnhomepage.fudan.edu.cn/...and-Decoder-in-NFC-Device.pdf · Coder and Decoder in NFC Device ... Anti-Collision in decoder 0 1

2012/2/4 5

Agenda

Overview Frame structure Design detail (problem and solution) Simulation result Conclusion

Page 6: Coder and Decoder in NFC Device - homepage.fudan.edu.cnhomepage.fudan.edu.cn/...and-Decoder-in-NFC-Device.pdf · Coder and Decoder in NFC Device ... Anti-Collision in decoder 0 1

2012/2/4 6

Code and modulate

Mode Speed Code Modulate Frequency Subcarrier

Target(A)/Initiator 106K bit/s Modified Miller ASK 100% fc/128

Target (A)/ Initiator 212K bit/s Manchester ASK 8%-30% fc/64

Target (A)/ Initiator 424K bit/s Manchester ASK 8%-30% fc/32

Target(P) 106K bit/s Manchester Load modulate

fc/16

Target(P) 212K bit/s Manchester Load modulate

fc/8

Target(P) 424K bit/s Manchester Load modulate

fc4

A—ActiveP—Passive

change clock frequency at different speed

Page 7: Coder and Decoder in NFC Device - homepage.fudan.edu.cnhomepage.fudan.edu.cn/...and-Decoder-in-NFC-Device.pdf · Coder and Decoder in NFC Device ... Anti-Collision in decoder 0 1

2012/2/4 7

Modified Miller

SOF

logic 0 following 1 logic 0 following 0 or SOF logic 1

EOF following 1

EOF following 0

Page 8: Coder and Decoder in NFC Device - homepage.fudan.edu.cnhomepage.fudan.edu.cn/...and-Decoder-in-NFC-Device.pdf · Coder and Decoder in NFC Device ... Anti-Collision in decoder 0 1

2012/2/4 8

Manchester

SOF (logic 1)

logic 1 logic 0

EOF

Page 9: Coder and Decoder in NFC Device - homepage.fudan.edu.cnhomepage.fudan.edu.cn/...and-Decoder-in-NFC-Device.pdf · Coder and Decoder in NFC Device ... Anti-Collision in decoder 0 1

2012/2/4 9

Load modulate

BP

Demo

Ri

RFE

Magnetic Filed H

T

BB

Switch control

DATA

1 0

Subcarrier

Manchester Code

Subcarrier modulate

Load modulate

Switch

Target to Initiator

Page 10: Coder and Decoder in NFC Device - homepage.fudan.edu.cnhomepage.fudan.edu.cn/...and-Decoder-in-NFC-Device.pdf · Coder and Decoder in NFC Device ... Anti-Collision in decoder 0 1

2012/2/4 10

Agenda

Overview Frame structure Design detail (problem and solution) Simulation result Conclusion

Page 11: Coder and Decoder in NFC Device - homepage.fudan.edu.cnhomepage.fudan.edu.cn/...and-Decoder-in-NFC-Device.pdf · Coder and Decoder in NFC Device ... Anti-Collision in decoder 0 1

2012/2/4 11

coder

clkrstmoderate[1:0]rolesof_eneof_enst

signal

ack

datain

0

128/fc32/fc

1

0

128/fc64/fc

1

rate 00/01/10 106K/212K/424K

role 0/1 target/ initiator

mode 0/1 passive/active

Idle Sof

datain

sof_en

Code Eof

eof_en

Idle

ack

xxx bit0 bit1 bitn xxx

state

Page 12: Coder and Decoder in NFC Device - homepage.fudan.edu.cnhomepage.fudan.edu.cn/...and-Decoder-in-NFC-Device.pdf · Coder and Decoder in NFC Device ... Anti-Collision in decoder 0 1

2012/2/4 12

Parity check in decoder

Bit0 Bit1 Bit2 Bit3 Bit4 Bit5 Bit6 Bit7 Parity

No parity in short frame which has only 7 bits

Need to register the state of CU and the number of bit

byte structure in sdandard frame

SDD frame part1

SDD frame part2

use a counter to count thenumber of “1”If count[0]=Parity =>error

Page 13: Coder and Decoder in NFC Device - homepage.fudan.edu.cnhomepage.fudan.edu.cn/...and-Decoder-in-NFC-Device.pdf · Coder and Decoder in NFC Device ... Anti-Collision in decoder 0 1

2012/2/4 13

Anti-Collision in decoder0

1

collision

need a collision flag to tell CUand register bit number

with different load modulation depth

with equivalent load modulation depth

Page 14: Coder and Decoder in NFC Device - homepage.fudan.edu.cnhomepage.fudan.edu.cn/...and-Decoder-in-NFC-Device.pdf · Coder and Decoder in NFC Device ... Anti-Collision in decoder 0 1

2012/2/4 14

Clock interrupt in decoder

0 0 1101

xxxx 7'b11111110 0 5'b11111 0 5'b11111

yyyy xxxx 7'b1111111 5'b11111

0 xxx

5'b11111

Sequence_r1

Sequence_r2

Shift_en

Page 15: Coder and Decoder in NFC Device - homepage.fudan.edu.cnhomepage.fudan.edu.cn/...and-Decoder-in-NFC-Device.pdf · Coder and Decoder in NFC Device ... Anti-Collision in decoder 0 1

2012/2/4 15

Decode strategy

Pre_data Sequence_r1 Sequence_r2 Current_data

sof 8'b00011111 1

sof 8'b00000111 0

1 8'b00000111 1

1 8'b00011111 0

0 8'b01111111 1

0 8'b00000111 0

Page 16: Coder and Decoder in NFC Device - homepage.fudan.edu.cnhomepage.fudan.edu.cn/...and-Decoder-in-NFC-Device.pdf · Coder and Decoder in NFC Device ... Anti-Collision in decoder 0 1

2012/2/4 16

Interface definition of decoder

clkrstmoderate[1:0]role

sof_flageof_flag

st

dataout

collision

signal

parityc_bit

bety_cpli

Idle Sof

dataout

sof_flag

Decode Eof

eof_flag

Idle

collision

xxx bit0 bit1bit7

11xxx

state

bit8

parity

Page 17: Coder and Decoder in NFC Device - homepage.fudan.edu.cnhomepage.fudan.edu.cn/...and-Decoder-in-NFC-Device.pdf · Coder and Decoder in NFC Device ... Anti-Collision in decoder 0 1

2012/2/4 17

Agenda

Overview Frame structure Design detail (problem and solution) Simulation result Conclusion

Page 18: Coder and Decoder in NFC Device - homepage.fudan.edu.cnhomepage.fudan.edu.cn/...and-Decoder-in-NFC-Device.pdf · Coder and Decoder in NFC Device ... Anti-Collision in decoder 0 1

2012/2/4 18

Coder

106K Initiator to Target 101001101

106K Target to Initiator 101001101

Page 19: Coder and Decoder in NFC Device - homepage.fudan.edu.cnhomepage.fudan.edu.cn/...and-Decoder-in-NFC-Device.pdf · Coder and Decoder in NFC Device ... Anti-Collision in decoder 0 1

2012/2/4 19

Decoder in initiator

Parity error

Collision

Page 20: Coder and Decoder in NFC Device - homepage.fudan.edu.cnhomepage.fudan.edu.cn/...and-Decoder-in-NFC-Device.pdf · Coder and Decoder in NFC Device ... Anti-Collision in decoder 0 1

2012/2/4 20

Decoder in target

Parity error

Decode successfully

Page 21: Coder and Decoder in NFC Device - homepage.fudan.edu.cnhomepage.fudan.edu.cn/...and-Decoder-in-NFC-Device.pdf · Coder and Decoder in NFC Device ... Anti-Collision in decoder 0 1

2012/2/4 21

Agenda

Overview Frame structure Design detail (problem and solution) Simulation result Conclusion

Page 22: Coder and Decoder in NFC Device - homepage.fudan.edu.cnhomepage.fudan.edu.cn/...and-Decoder-in-NFC-Device.pdf · Coder and Decoder in NFC Device ... Anti-Collision in decoder 0 1

2012/2/4 22

Conclusion

Design the coder and decoder of NFC device witch operate in P2P mode

Decoder support anti_collision and parity Solve the problem of clock interrupt when

100% modulation depth used

Page 23: Coder and Decoder in NFC Device - homepage.fudan.edu.cnhomepage.fudan.edu.cn/...and-Decoder-in-NFC-Device.pdf · Coder and Decoder in NFC Device ... Anti-Collision in decoder 0 1

2012/2/4 23

Thank you !

Q&A