AM79C875KI AMD (ADVANCED MICRO DEVICES), AM79C875KI Datasheet - Page 32

• Manufacturer Part Number: AM79C875KI
• Manufacturer: AMD (ADVANCED MICRO DEVICES)

Specifications of AM79C875KI

• Lead Free Status / RoHS Status: Not Compliant

Diagnostic Register (Register 18)
Test Register (Register 19)
Miscellaneous Features 2 Register (Register 20)
32
Reg
Reg
Reg
19
19
19
19
19
19
20
20
20
20
18
18
18
18
18
18
15:12
15:12
15:12
11:8
11:8
7:4
3:0
Bit
Bit
7:0
Bit
4:0
11
10
9
8
7
6
5
Compliance Test
Cable length
10/100 Mbps
Reserved
Reserved
Reserved
RX_LOCK
RX_PASS
Reserved
Reserved
Reserved
Reserved
indicator
Reserved
Reserved
Transmit
Name
Name
1.25:1
Speed
Name
DPLX
Table 20. Miscellaneous Features 2 Register (Register 20)
Description
Ignore when read, write as Default (0x0110).
Ignore when read, write as Default (0x1001).
These bits are the cable length indicators. Increment from 0000 to
1111, or approximately every 10 meters. The equivalent is 0 to 32dB
with an increment of 2dB @ 100Mhz. The value is read back from the
equalizer, and the measured value is not absolute.
Ignore when read.
Description
Ignore when read, write as Default (0x1000).
Ignore when read, write as Default (0x0010).
Ignore when read, write as 0.
Selects transformer ratio.
1 = 1.25:1
0 = 1:1
The default value is controlled by the TP1_1 pin.
This bit controls internal logic, including power-saving circuitry. For 10
and 100 Mbps transmit compliance testing ONLY, this bit must be
turned off, but should be turned on for normal operation. The default
is 1 (on).
1 = Normal operation.
0 = Compliance test mode.
Ignore when read, write as 0.
Table 18. Diagnostic Register (Register 18)
Description
Ignore when read.
This bit indicates the result of the Auto-Negotiation for duplex
arbitration.
1 = Full Duplex.
0 = Half Duplex.
This bit indicates the result of the Auto-Negotiation for data speed
arbitration.
1 = 100 Mbps.
0 = 10 Mbps.
In 10BASE-T mode, a 1 indicates that Manchester data has been
detected.
In 100BASE-TX mode, a 1 indicates a valid signal has been
received but not necessarily locked onto.
1 = Received RLL has locked onto the received signal for selected
data-rate (10BASE-T or 100BASE-TX)
0 = Receive PLL has not locked onto received signal.
This bit remains set until read.
Ignore when read.
Table 19. Test Register (Register 19)
Am79C875
RO/RC
Read/
Read/
Write
Write
Read/
Write
RW
RW
RW
RW
RW
RW
RW
RW
RO
RO
RO
RO
RO
RO
RO
Default
0x1001
0x0010
0x0110
Default
0x1000
0x0010
Default
0x22
0
0
0
1
0
0
0
0
0
0