Motorola MPC823e Reference Manual page 801

TXB—TX Buffer
This bit indicates that a buffer has been transmitted on the Ethernet channel.
RXB—RX Buffer
This bit indicates that a buffer that was not a complete frame was received on the Ethernet
channel.
FRAME
RECEIVED IN ETHERNET
TIME
RXD
LINE IDLE
RENA
ETHERNET SCCE
EVENTS
NOTES:
1. RXB event assumes receive buffers are 64 bytes each.
2. The RENA events, if required, must be programmed in the port C parallel I/O, not in the SCC itself.
3. The RXF interrupt may occur later than RENA due to receive FIFO latency.
LEGEND:
P = Preamble, SFD = Start Frame Delimiter, DA and SA = Source/Destination Address, T/L = Type/Length,
D = Data, and CR = CRC bytes.
FRAME
TRANSMITTED BY ETHERNET
LINE IDLE
TXD
TENA
CLSN
HDLC SCCE
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.
3. The TENA or CLSN events, if required, must be programmed in the port C parallel I/O, not in the SCC itself.
Figure 16-110. Ethernet Interrupt Events Example
MOTOROLA
STORED IN RX BUFFER
P SFD DA SA T/L D
RXB
STORED IN
TX BUFFER
P SFD DA SA T/L D
TXB
MPC823e REFERENCE MANUAL
Communication Processor Module
CR LINE IDLE
RXF
CR LINE IDLE
TXB
GRA
16-347