Rainbow-electronics AT89C51SND1C Instrukcja Użytkownika Pobierz pdf (Strona 82)

AT8xC51SND1C

4109E–8051–06/03

Serial Interface Engine (SIE) The SIE performs the following functions:

• NRZI data encoding and decoding.

• Bit stuffing and unstuffing.

• CRC generation and checking.

• ACKs and NACKs automatic generation.

• TOKEN type identifying.

• Address checking.

• Clock recovery (using DPLL).

Figure 57. SIE Block Diagram

Start of Packet

Detector

Clock

Recover

SYNC Detector

PID Decoder

Address Decoder

Serial to Parallel

Converter

CRC5 & CRC16

Generator/Check

USB Pattern Generator

Parallel to Serial Converter

Bit Stuffing

NRZI Converter

CRC16 Generator

NRZI ‘ NRZ

Bit Unstuffing

Packet Bit Counter

End of Packet

Detector

USB

CLOCK

48 MHz

SysClk

Data In

D+

D-

(12 MHz)

Data Out

1 2 ... 77 78 79 80 81 82 83 84 85 86 87 ... 209 210

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Rainbow-electronics AT89C51SND1C Instrukcja Użytkownika Strona 82