AM79C988 데이터 시트보기 (PDF) - Advanced Micro Devices
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AM79C988 Datasheet PDF : 25 Pages
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PRELIMINARY
Link Status
B0B1B2B3
The QuIET device reports the Link Status of each port.
If Link Test is disabled, Link Status indicates a Link Pass.
Bn
0
1
Link Fail
Link Pass
Receive Polarity Status
C0C1C2C3
The QuIET device reports the polarity status of each port.
Cn
0
1
Reversed Polarity
True Polarity
Jabber Condition
D0D1D2D3
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.
Dn
0
1
No Jabber
Jabber
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.
Management Command Format
0E0E1E2E3F0F1F2F3G0G1G2G3H0H1H2H3I J0J1J2J3KSSSSSSS
En Extended Distance
0 Disabled
1 Enabled
Fn Link Test
0 Disabled
1 Enabled
Gn Transmit Link Test Pulses 0 Disabled
1 Enabled
Hn Enable Polarity Correc-
tion
0 Enabled
1 Disabled
I
Loopback Test (All Ports) 0 Enabled
1 Disabled
Jn Transceiver Mode
0 Full Duplex
1 Normal (Default
condition - IMR2 only
supports Normal)
K CMOS/PAUI Mode
0 CMOS Mode
1 PAUI Mode
S Not used
Logic HIGH
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.
Extended Distance Option
E0E1E2E3
This command modifies the RXD circuit of the trans-
ceiver to accommodate signal-attenuation lines longer
than 100 meters.
En
0 Disable Extended Distance Option
1 Enable Extended Distance Option
Link Test Enable
F0F1F2F3
This command enables the corresponding port to per-
form a Link Test. Link Status will report Link Pass if the
Link Test is disabled.
Fn
0
1
Disable Link Test
Enable Link Test
Transmit Link Pulse Enable
G0G1G2G3
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.
Gn
0
1
Disable Link Pulse Transmit
Enable Link Pulse Transmit
Auto Polarity Correction Enable
H0H1H2H3
This command allows the QuIET device to detect and
correct the polarity of signals at RXD.
Hn
0
1
Enable Auto Polarity
Disable Auto Polarity
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
0
Enable Loopback Test
1
Disable Loopback Test
Transceiver Mode Selection
J0J1J2J3
This command sets the QuIET device either in Full-Du-
plex or Normal mode. The default is Normal mode.
Jn
0
1
Full Duplex
Normal
10
Am79C988A
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