Maxim Integrated MAXQ622 - Manual (Page 173)

MAXQ612/MAXQ622 User’s Guide
Maxim Integrated 12-3
12.2 USB SIE Features
The hardware SIE does most of the signaling work required by the USB protocol, such as the following:
1) Timing recovery based on the incoming data stream (differential receiver output)
2) USB packet PID detection and checking
3) CRC check and generation
4) USB packet generation
5) NRZI data encoding and decoding
6) Bit stuffing and unstuffing
7) Various USB error condition detection
8) USB bus reset, suspend, and wake-up detection
9) USB resume signaling
The following sections list the control registers dedicated to the USB SIE . Note that all USB pins are dedicated, and so
none of them are multiplexed with GPIO port pins .
Figure 12-3. USB SIE Block Diagram
VPO
VMO
OE
VPI
VMI
RCV
MODE
SUSPEND
BUSACT
SOF
VBUSDET
ENCODER
PROTOCOL LOGIC
DPLL
EOP
DECODER
ENDPOINT BUFFER LOGIC
TO DUAL PORT—SRAM
TIMER
SIE