Rainbow Electronics AT89C5122 - Manual (Page 97)

97
AT8xC5122/23
4202E–SCR–06/06
Figure 50. SIE Block Diagram
Function Interface Unit (UFI) The Function Interface Unit provides the interface between the AT8xC5122D (or
AT83C5123) and the SIE. It manages transactions at the packet level with minimal inter-
vention from the device firmware, which reads and writes the endpoint FIFOs.
Figure 51. UFI Block Diagram
End of Packet
Detection
Start of Packet
Detection
D+
D-
Clock
Recovery
SYNC detection
PID decoder
Address Decoder
Se ria l to Para ll el
Conversion
CRC5 & CRC16
Generation/Check
USB Pattern Generator
Parallel to Serial Converter
Bit Stuffing
NRZI Converter
CRC16 Generator
NRZI ‘ NRZ
Bit Unstuffing
Packet bit counter
Clk48
(48 MHz)
SysClk
(12 MHz)
DataIn [7:0]
DataOut
8
8
Transfer
Control
FSM
DPR Control
USB side
CSREG 0 to 7
Registers
Bank
DPR Control
mP side
UFI
User DPRAM
Up to 48 MHz
UC_SYSCLK
C51
Microcontroller
Interface Asynchronous Information
Transfer
Endpoint 0
Endpoint 1
Endpoint 2
Endpoint 3
SIE
DPLL
Endpoint 4
Endpoint 5
Endpoint 6