Excessive Deferral on this trans-
mit frame, where Excessive De-
ferral is defined in the ISO 8802-3
(IEEE/ANSI 802.3) standard. Ex-
cessive Deferral will also set the
interrupt bit EXDINT (CSR5, bit
7).
26
RTRY
Retry error indicates that the
transmitter has failed after 16 at-
tempts to successfully transmit a
message, due to repeated colli-
sions on the medium. If DRTY is
set to 1 in the MODE register,
RTRY will set after one failed
transmission attempt. RTRY is
set by the Am79C978 controller
and cleared by the host.
28
LCOL
Late Collision indicates that a col-
lision has occurred after the first
channel slot time has elapsed.
The
Am79C978
home
25-4 RES
Reserved locations.
networkingAm79C978 controller
does not retry on late collisions.
LCOL is set by the Am79C978
controller and cleared by the
host.
3-0
TRC
Transmit Retry Count. Indicates
the number of transmit retries of
the associated packet. The maxi-
mum count is 15. However, if a
RETRY error occurs, the count
will roll over to 0.
27
LCAR
Loss of Carrier is set when the
carrier is lost during an
Am79C978 controller initiated
transmission when operating in
In this case only, the Transmit
Retry Count value of 0 should be
interpreted as meaning 16. TRC
is written by the Am79C978 con-
troller into the last transmit de-
scriptor of a frame, or when an
error terminates a frame. Valid
only when OWN is cleared to 0.
half-duplex
mode.
The
Am79C978 controller does not
retry upon loss of carrier. It will
continue to transmit the whole
frame until done. LCAR will not
be set when the device is operat-
ing in full-duplex mode. LCAR is
not valid in Internal Loopback
Mode. LCAR is set by the
TMD3
Bit
Name
Description
Am79C978
cleared by the host.
controller
and
31-0 US
User Space. Reserved for user
defined space.
LCAR will be set when the PHY is
in Link Fail state during transmis-
sion.
206
Am79C978
AMD [ AMD ]
