Intel 249323-003 User Manual
LXD9785 PQFP Demo Board with FPGA for SS-SMII (Fiber)-to-MII Conversion
Development Kit Manual
17
Document #: 249323
Revision #: 003
Rev. Date: January 24, 2002
Revision #: 003
Rev. Date: January 24, 2002
5.0
LEDs
5.1
Direct Drive LEDs
The LXD9785 PQFP MII Demo Board provides three programmable LED drivers per port (D4 -
D28). Each LED can display one of several available status conditions as selected by the LED
Configuration Register (Address 20) shown in
D28). Each LED can display one of several available status conditions as selected by the LED
Configuration Register (Address 20) shown in
.
.
The programmable LEDs (LED_1, LED_2, and LED_3) are set in the default mode and are
programmable via 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 as shown in
programmable via 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 as shown in
.
Table 8. Direct Drive LED Configuration Settings (Register 20)
LED Bits
Program
Bits
Description
LED1
LED2
LED3
15:12
11:8
7:4
0000
Indicates 100 Mbps operation. (Default for LED1)
0001
Indicates transmit (Stretched).
0010
Indicates receive (stretched). (Default for LED3)
0011
Indicates collision (Stretched).
0100
Indicates active link (continuous). (Default for LED2)
0101
Indicates full-duplex.
0110
Reserved.
0111
Indicates transmit or receive activity.
1000
Test Mode. Turn LED on (continuous).
1001
Test Mode. Turn LED off (continuous).
1010
Test Mode. Blink LED fast (continuous).
1011
Test Mode. Blink LED slow (continuous).
1100
Indicates link and receive status combined
1
(Stretched)
2
.
1101
Indicates link and activity status combined
1
(Stretched)
2
.
1110
Indicates duplex and collision status combined
3
(Stretched)
2
.
1111
Reserved.
1. Link status is the primary LED driver. The LED is asserted (solid ON) when the link is up. The secondary
LED driver (receive, activity, or isolate) causes the LED to change state (blink).
2. Combined event LED settings are not affected by bit 20.1 (Pulse Stretch). These settings are stretched
regardless of the value of 20.1.
3. Duplex status is the primary LED driver. The LED is asserted (solid ON) when the link is full-duplex.
Collision status is the secondary LED driver. The LED changes state (blinks) when a collision occurs.