Datasheet

121
4337K–USB–04/08
AT89C5130A/31A-M
• Address checking.
• Clock generation (via DPLL).
Figure 21-2. SIE Block Diagram
21.1.2 Function Interface Unit (FIU)
The Function Interface Unit provides the interface between the AT89C5131 and the SIE. It man-
ages transactions at the packet level with minimal intervention from the device firmware, which
reads and writes the endpoint FIFOs.
End of Packet
Detection
Start of Packet
Detection
D+
D-
Clock
Recovery
SYNC Detection
PID Decoder
Address Decoder
Serial to
P a r a l l e l
CRC5 and CRC16
Generation/Check
USB Pattern Generator
Parallel to Serial Converter
Bit Stuffing
NRZI Converter
CRC16 Generator
NRZI ‘NRZ
Bit Un-stuffing
Packet Bit Counter
Clk48
(48 MHz)
SysClk
(12 MHz)
DataIn [7:0]
DataOut
8
8