Maxim Integrated DS33R11 - Manual (Page 180)

DS33R11 Ethernet Mapper with Integrated T1/E1/J1 Transceiver
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Register Name:
SU.TFSL
Register Description: Transmit Frame Status Low
Register Address: 152h
Bit
# 7 6 5 4 3 2 1 0
Name UR EC LC ED LOC NOC - FABORT
Default 0 0 0 0 0 0 0 0
Bit 7: Under Run (UR) When this bit is set to 1, the frame was aborted due to a data under run condition of the
transmit buffer.
Bit 6: Excessive Collisions (EC) When this bit is set to 1, a frame has been aborted after 16 successive collisions
while attempting to transmit the current frame. If the Disable Retry bit is set to 1, then Excessive Collisions will be
set to 1 after the first collision.
Bit 5: Late Collision (LC) When this bit is set to 1, a frame was aborted by collision after the 64 bit collision
window. Not valid if an under run has occurred.
Bit 4: Excessive Deferral (ED) When this bit is set to 1, a frame was aborted due to excessive deferral.
Bit 3: Loss Of Carrier (LOC) When this bit is set to 1, a frame was aborted due to loss of carrier for one or more
bit times. Valid only for noncollided frames. Valid only in half-duplex operation.
Bit 2: No Carrier (NOC) When this bit is set to 1, a frame was aborted because no carrier was found for
transmission.
Bit 1: Reserved
Bit 0: Frame Abort (FABORT) When this bit is set to 1, the MAC has aborted a frame for one of the above
reasons. When this bit is clear, the previous frame has been transmitted successfully.
Register Name:
SU.TFSH
Register Description: Transmit Frame Status High
Register Address: 153h
Bit
# 7 6 5 4 3 2 1 0
Name PR HBF CC3 CC2 CC1 CC0 LCO DEF
Default 0 0 0 0 0 0 0 0
Bit 7: Packet Resend (PR) When this bit is set, the current packet must be retransmitted due to a collision.
Bit 6: Heartbeat Failure (HBF) When this bit is set, the device failed to detect a heart beat after transmission. This
bit is not valid if an under run has occurred.
Bits 2-5: Collision Count (CC0-3) These 4 bits indicate the number of collisions that occurred prior to successful
transmission of the previous frame. Not valid if Excessive Collisions is set to 1.
Bit 1: Late Collision (LCO) When set to 1, the MAC observed a collision after the 64-byte collision window.
Bit 0: Deferred Frame (DEF) When set to 1, the current frame was deferred due to carrier assertion by another
node after being ready to transmit.