AM79C875KI AMD (ADVANCED MICRO DEVICES), AM79C875KI Datasheet - Page 22

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

Specifications of AM79C875KI

• Lead Free Status / RoHS Status: Not Compliant

nected ports and ports running at 10 or 100 Mbps with
Auto-Negotiation disabled. Typical power becomes
100 mW per port.
Power Down
Most of the NetPHY™ 4LP device can be disabled via
the Power Down bit in Register 0, bit 11. Setting this bit
on Register 0 of any port will power down the respec-
tive port with the exception of the MDIO/MDC manage-
ment circuitry. Typical power becomes 5 mW or lower
per port.
LED Port Configuration
The NetPHY™ 4LP device has several pins that are
used for both device configuration and LED drivers.
These pins set the configuration of the device on the
rising edge of RST and thereafter indicate the state of
the respective port. See Table 2.
Notes:
1. N = PHY port number (0...3)
2. X = don’t care
Note: LEDXXX/XXX = any LED pin.
22
Cable Connected (Link)
100Mbps, Half Duplex
100Mbps, Full Duplex
10Mbps, Half Duplex
10Mbps, Full Duplex
RMII mode: Activity
1 - 4.7 kΩ
Configure LOW with an
Blinks on Transmit/Receive Activity
Active-HIGH LED
LEDACT_LINK[N]
Table 2.
Figure 8. LED Port Configuration
R L
LED On
LED On
LED On
LED On
LED On
LEDXXX/XXX
LED Display Configuration
Am79C875
1 - 4.7 kΩ
The polarity of the LED drivers (Active-LOW or Active-
HIGH) is set at the rising edge of RST. If the pin is LOW
at the rising edge of RST, it becomes an active-HIGH
driver. If it is HIGH at the rising edge of RST, it becomes
an active-LOW driver.
Proper configuration requires external pull-up or pull-
down resistors. If the LED corresponding to a pin is not
used, the pin must be terminated via a resistor. The re-
sistor value is not critical and can be in the range of
1 KΩ to 4.7 KΩ. If the corresponding LED is used, the
terminating resistor must be placed in parallel with the
LED. Figure 8 illustrates the wiring of the LEDs for both
configuration settings.
The value of the series resistor (R
to ensure sufficient illumination of the LED. It is
dependent on the rating of the LED.
Configure HIGH with an
Active-LOW LED
LEDSPD[N]
V
LED Off
LED On
LED On
LED Off
LED Off
DD
X
R L
LEDXXX/XXX
L
) should be selected
LEDDPX[N]
LED Off
LED Off
LED On
LED Off
LED On
X
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