Intel LXD972M Mdio Configuration Options, LED Configuration Options, Clock Configuration Options

Intel® LXD972M Transceiver Demo Board (Board Rev A1)

Table 7 lists clock configuration options.

Table 7. Clock Configuration Options

Desired	JP18 Settings		Description
Configuration
	Pins 11, 2	Open	Remove jumper from pins 1 and 2 to disable the clock oscillator Y2
Enable Crystal			output.
Oscillator Y1	Pins 3, 4	Jumper	Place a jumper on pins 3 and 4 and pins 5 and 6, which connects a
	Pins 5, 6		crystal across XI and XO to enable Y1.
	Pins 1, 2	Jumper	Place a jumper on pins 1 and 2, which enables the output of clock
Enable Clock			oscillator Y2.
Oscillator Y2	Pins 3, 4	Open	Remove jumper from pins 3 and 4, and remove jumper from pins 5
	Pins 5, 6		and 6, which disables a crystal connection across XI and XO to Y1.
1. Pin 1 is located on the lower-right corner of JP18.

2.4.3MDIO Configuration Options

The default configuration of the MDIO and MDC signals is to route the MDIO through the MII connector to the SmartBits Test Box by installing jumpers JP16 and JP17.

Note: The RJ-11 feature is not supported. As a result, do not jumper the MDIO and MDC signals to the RJ-11 connector.

Table 8 lists the desired MDIO configuration settings.

Table 8. MDIO Configuration Options

Desired Configuration	Jumper	Setting		Description
Route MDIO and MDC	JP16	Jumper	Pins 2, 3	Routes MDIO through 40-pin MII Connector P1
through MII	JP17	Jumper	Pins 2, 3	Routes MDC through 40-pin MII Connector P1
Route MDIO and MDC	JP16	Jumper	Pins 1, 2	Routes MDIO through RJ-11 Connector J2
through RJ-11	JP17	Jumper	Pins 1, 2	Routes MDC through RJ-11 Connector J2

2.4.4LED Configuration Options

The LXD972M Demo Board provides three programmable LEDs. Each LED can display one of several available status conditions as selected by the LED Configuration Register (Address 20). Programmable LEDs (LED/CFG1, LED/CFG2, LED/CFG3) are set in default mode and are programmable with the MDIO pin. Register address 20 also provides optional LED pulse stretching up to 100 ms. Register bits 20.3:2 select one of three possible stretch times. (For details, see the LXT972M Transceiver datasheet.)

Note: The active LED state is determined by the CFG pin function. When the LED/CFG pin is pulled High, the LED becomes active Low. When the LED/CFG pin is pulled Low, the LED becomes active High.

Preliminary User’s Guide 13

Document Number: 303125

Revision Number: 002

Revision Date: October 22, 2004