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Cortina Systems LXT9785 and LXT9785E Advanced 8-Port 10/100 Mbps PHY Transceivers
LXT9785/LXT9785E
Datasheet
249241, Revision 11.0
16 April 2007
7.0 Register Definitions
7:4
LED3
Programming
bits
0000 =Display Speed Status
0001 =Display Transmit Status
0010 =Display Receive Status
0011 = Display Collision Status
0100 =Display Link Status
0101 =Display Duplex Status
0110 = Display Isolate Status
0111 = Display Receive or Transmit Activity
1000 =Test mode- turn LED on
1001 =Test mode- turn LED off
1010 =Test mode- blink LED fast
1011 = Test mode- blink LED slow
1100 = Display Link and Receive Status combined2
(Stretched)3
1101 = Display Link and Activity Status combined2
(Stretched)3
1110 = Display Duplex and Collision Status combined4
(Default) (Blink)3
1111 = Display Link and RxER Status combined 2 (Blink)
R/W
1110
3:2
LEDFREQ
00 = Stretch LED events to 30 ms
01 = Stretch LED events to 60 ms
10 = Stretch LED events to 100 ms
11 = Reserved
R/W
00
1
PULSE-
STRETCH
0 = Disable pulse stretching of all LEDs3
1 = Enable pulse stretching of all LEDs
Note:
Receive activity LEDs are initially active based upon
carrier sense.
R/W
1
0
Reserved
Write as 0, ignore on Read
R/W
0
Table 98
Receive Error Count Register (Address 21, Hex 15)
Bit
Name
Description
Type1
Default
15:0
Receive Error
Count
A 16-bit counter value indicating the number of times a
receive packet with errors occurred. Only one event gets
counted per packet. When maximum count is reached, the
16-bit counter remains full until cleared.
R/
LH
0x0000
1. R = Read Only, LH = Latching High – cleared when read
Note:
Cortina recommends reading this register once every time link is established to clear the register.
Table 97
LED Configuration Register (Address 20, Hex 14)
Bit
Name
Description
Type1
Default
1. R/W = Read/Write
2. 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 Error) causes the LED to change state (blink).
3. Combined event LED settings are not affected by Pulse Stretch Register bit 20.1. These display settings
are stretched regardless of the value of 20.1.
4. 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.