HBLXT9761HC.C4 Intel, HBLXT9761HC.C4 Datasheet - Page 28

• Manufacturer Part Number: HBLXT9761HC.C4
• Manufacturer: Intel

Specifications of HBLXT9761HC.C4

• Lead Free Status / RoHS Status: Not Compliant

LXT9761/9781 — Fast Ethernet 10/100 Multi-Port Transceiver with RMII
2.4.4
2.4.5
.
28
Figure 11. Hardware Control Settings
Note: Auto-Negotiation must be disabled before selecting fiber operation.
Reset
The LXT97x1 provides both hardware and software resets. Configuration control of Auto-
Negotiation, speed and duplex mode selection is handled differently for each. During a hardware
reset, settings for bits 0.13, 0.12 and 0.8 are read in from the pins (refer to
pin settings and to
During a software reset (0.15 = 1), these bit settings are not re-read from the pins. They revert back
to the values that were read in during the last hardware reset. Therefore, any changes to pin values
made since the last hardware reset will not be detected during a software reset.
During a hardware reset, register information is unavailable for 1 ms after de-assertion of the reset.
During a software reset (0.15 = 1) the registers are available for reading. The reset bit should be
polled to see when the part has completed reset (0.15 = 0).
Hardware Configuration Settings
The LXT97x1 provides a hardware option to set the initial device configuration. The hardware
option uses the three LED/CFG driver pins for each port. This provides three control bits per port,
as listed in
shown in
or pull down to configure for either open drain or open source circuits (10 mA max current rating)
as required by the hardware configuration. In applications where all ports are configured the same,
several pins may be tied together with a single resistor.
LED/CFG Pin
LED/CFG Pin
1. LEDs will automatically correct their
Figure
Table
polarity upon power-up or reset.
11.
9. The LED drivers can operate as either open drain or open source circuits as
Table 35 on page 65
Configuration Bit = 0
The LED/CFG pins are sensitive to polarity and will automatically pull up
Configuration Bit = 1
for register bit definitions).
VCC
Table 9 on page 29
Datasheet
for