am79c988a ETC-unknow, am79c988a Datasheet - Page 10

• Manufacturer Part Number: am79c988a
• Description: Quad Integrated Ethernet Transceiver Quiet
• Manufacturer: ETC-unknow

Management Command Format
Link Status
B
The QuIET device reports the Link Status of each port.
If Link Test is disabled, Link Status indicates a Link Pass.
B
Receive Polarity Status
C
The QuIET device reports the polarity status of each port.
C
Jabber Condition
D
The QuIET device reports the Jabber Condition status
for each port. Jabber is defined as continuous transmis-
sions by a port for more than 30 ms.
D
Management Commands
When DIR switches from LOW to HIGH, the QuIET de-
vice reads the command sequence over SDATA. Each
management command character is held for 2-bit times
(200 ns). The command format is as follows.
0E
Note : The QuIET device requires DIR to be high for a
minimum of 29 data bits (one bit is four MCLKs), which
automatically occurs with the IMR2 device. If any other
type of controller is used, DIR must still be high at least
29-bit times. After I, SDATA can be all ones.
10
0
n
0
n
0
n
E
F
G
H
I
J
K
S
0
B
C
D
E
n
n
n
n
n
1
1
1
1
E
B
C
D
2
E
2
2
2
3
B
C
D
F
Extended Distance
Link Test
Transmit Link Test Pulses
Enable Polarity Correc-
tion
Loopback Test (All Ports)
Transceiver Mode
CMOS/PAUI Mode
Not used
0
3
3
3
F
1
F
0
1
0
1
0
1
2
F
3
G
0
G
1
G
2
G
3
H
0
H
Link Fail
Link Pass
Reversed Polarity
True Polarity
No Jabber
Jabber
1
H
2
H
3
I J
0
J
1
0 Disabled
1 Enabled
0 Disabled
1 Enabled
0 Disabled
1 Enabled
0 Enabled
1 Disabled
0 Enabled
1 Disabled
0 Full Duplex
1 Normal (Default
condition - IMR2 only
supports Normal)
0 CMOS Mode
1 PAUI Mode
Logic HIGH
J
2
J
3
KSSSSSSS
P R E L I M I N A R Y
Am79C988A
Extended Distance Option
E
This command modifies the RXD circuit of the trans-
ceiver to accommodate signal-attenuation lines longer
than 100 meters.
E
Link Test Enable
F
This command enables the corresponding port to per-
form a Link Test. Link Status will report Link Pass if the
Link Test is disabled.
F
Transmit Link Pulse Enable
G
This command enables the corresponding port to trans-
mit a Link Pulse. The pulse will be transmitted if either
a packet or a pulse has not been transmitted for 16 ms.
Note that Link Pulses are transmitted when ports are in
Link Test Fail.
G
Auto Polarity Correction Enable
H
This command allows the QuIET device to detect and
correct the polarity of signals at RXD.
H
Loopback Test Enable
This command enables or disables the loopback test
for the twisted pair ports. When enabled, the signal on
RXD is retransmitted on TXD. The default condition is
loopback test disabled. Note that the TXD drivers have
on-chip filtering, which may cause the TXD output to
be different from the corresponding RXD input during
this test.
I
Transceiver Mode Selection
J
This command sets the QuIET device either in Full-Du-
plex or Normal mode. The default is Normal mode.
J
0
n
0
n
0
n
0
n
0
n
J
F
E
H
G
1
1
1
1
J
1
F
E
H
2
G
2
J
2
2
F
2
E
3
H
G
3
3
3
3
0 Disable Extended Distance Option
1 Enable Extended Distance Option
0
1
0
1
0
1
0
1
0
1
Disable Link Test
Enable Link Test
Disable Link Pulse Transmit
Enable Link Pulse Transmit
Enable Auto Polarity
Disable Auto Polarity
Enable Loopback Test
Disable Loopback Test
Full Duplex
Normal