AT8xC51SND2C
Serial Interface Engine (SIE)
The SIE performs the following functions:
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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 65. SIE Block Diagram
End of Packet
Detector
SYNC Detector
PID Decoder
Start of Packet
Detector
NRZI ‘ NRZ
Bit Unstuffing
Packet Bit Counter
Address Decoder
Serial to Parallel
Converter
D+
D-
8
Data Out
Clock
Recover
SysClk
(12 MHz)
USB
CLOCK
48 MHz
CRC5 & CRC16
Generator/Check
USB Pattern Generator
Parallel to Serial Converter
Bit Stuffing
8
Data In
NRZI Converter
CRC16 Generator
105
4341D–MP3–04/05
ATMEL [ ATMEL ]
