K60P100M100SF2RM Datasheet, PDF (1192/1809 Pages) Freescale Semiconductor, Inc – K60 Sub-Family Reference Manual

Functional Description
• Generates preamble and SFD field before frame transmission
• Generates XOFF pause frames if the receive FIFO reports a congestion or if
ENETn_TCR[TFC_PAUSE] is set with ENETn_OPD[PAUSE_DUR] set to a non-
zero value
• Generates XON pause frames if the receive FIFO congestion condition is cleared or
if TFC_PAUSE is set with PAUSE_DUR cleared
• Suspends Ethernet frame transfer (XOFF) if a non-zero pause quanta is received
from the MAC receive path
• Adds padding to the frame if required
• Calculates and appends CRC-32 to the transmitted frame
• Send frame with correct inter-packet gap (IPG) (deferring)
When the MAC is configured to operate in half duplex mode, the following additional
tasks are performed:
• Collision detection
• Frame retransmit after back-off timer expires
Send Preamble
Send destination address
Send local MAC address
(overwrite FIFO data)
Send payload
Send padding
(if necessary)
Send CRC
Figure 44-56. Frame Transmit Overview
44.4.5.1 Frame Payload Padding
The IEEE specification defines a minimum frame length of 64 bytes.
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K60 Sub-Family Reference Manual, Rev. 6, Nov 2011
Freescale Semiconductor, Inc.