Motorola PowerQUICC II MPC8280 Series Reference Manual page 1331

Figure 36-8 shows interrupts that can be generated in the Ethernet protocol.
Frame
Received in Ethernet
Time
RXD Line Idle
RX_DV
Ethernet FCCE
Events
Notes:
1. RXB event assumes receive buffers are 64 bytes each.
2. The RXF interrupt may occur later than RX_DV due to receive FIFO latency.
Frame
Transmitted by Ethernet
TXD Line Idle
TX_EN
COL
Ethernet FCCE
Events
Notes:
1. TXB events assume the frame required two transmit buffers.
2. The GRA event assumes a graceful stop transmit command was issued during frame transmission.
Legend:
P = Preamble, SFD = Start frame delimiter, DA and SA = Destination/Source address,
T/L = Type/Length, D = Data, CR = CRC bytes
Figure 36-8. Ethernet Interrupt Events Example
The FCC status register is not valid for the Ethernet protocol.
The current state of the MII signals can be read through the
parallel ports.
36.19 Ethernet RxBDs
The Ethernet controller uses the RxBD to report information about the received data for
each buffer. Figure 36-9 shows the FCC Ethernet RxBD format.
MOTOROLA
Freescale Semiconductor, Inc.
Stored in Rx Buffer
P SFD DA SA T/L
Stored in Tx Buffer
P SFD DA SA T/L
TXB
NOTE
Chapter 36. Fast Ethernet Controller
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D CR Line Idle
RXB RXF
D CR Line Idle
TXB, GRA
Ethernet RxBDs
36-25