Description
Reset
Type
Name
Bit/Field
Software should not rely on the value of a reserved bit. To provide
compatibility with future products, the value of a reserved bit should be
preserved across a read-modify-write operation.
0x0
RO
reserved
21
Jumbo Frame Enable
When this bit is set, the MAC allows jumbo frames of 9,018 bytes (9,022
bytes for VLAN tagged frames) without reporting a giant frame error in
the receive frame status.
Description
Value
Jumbo frames create giant frame error.
0
Jumbo frames allowed without error.
1
0x0
RW
JFEN
20
Inter-Frame Gap (IFG)
These bits control the minimum IFG between frames during transmission.
Description
Value
96 bit times
0x0
88 bit times
0x1
80 bit times
0x2
72 bit times
0x3
64 bit times
0x4
56 bit times
0x5
48 bit times
0x6
40 bit times
0x7
In half-duplex mode, the minimum IFG can be configured only for 64 bit
times (IFG = 0x4). Lower values are not considered.
0x0
RW
IFG
19:17
Disable Carrier Sense During Transmission
When this bit is set, the MAC transmit module ignores carrier sense in
half-duplex mode. Thus, errors are not generated when there is a loss
of carrier or no carrier during transmission. When this bit is clear, the
MAC transmitter generates errors because of carrier sense and can
even abort the transmissions.
Description
Value
Generate errors for carrier sense errors.
0
Ignore carrier sense errors.
1
0x0
RW
DISCRS
16
Port Select
This bit indicates that a 10/100 Mbps interface is supported on this
device. This is a read-only bit.
1
RO
PS
15
Speed
This bit indicates the speed of the interface.
Description
Value
10 Mbps
0
100 Mbps
1
0
RW
FES
14
1473
June 18, 2014
Texas Instruments-Production Data
Tiva
™
TM4C1294NCPDT Microcontroller