3X38FTR Datasheet, PDF (42/64 Pages) Agere Systems – OCTAL-FET (Fast Ethernet Transceiver) for 10Base-T/100Base-TX/FX

3X38FTR 208-Pin SQFP
OCTAL-FET for 10Base-T/100Base-TX/FX
Preliminary Data Sheet
September 2000
Functional Description (continued)
CLK
DATA
STROBE
0
1
2
3
4
5
6
7
8
9
0
C 4C 3C 2C 1C 0 AC L 1S P F DC L 1
CLK
1
2
3
4
5
6
7
8
9
0
1
DATA B A P R S X S
STROBE
CLK
DATA
STROBE
CLK
DATA
STROBE
2
3
4
5
6
7
8
9
0
1
0
1
2
3
4
5
6
7
8
9
0
C 4C 3C 2C 1C 0 A C L 1S P FDC L 1
Figure 14. Timing Diagram
5-7897(F).r1
Bicolor LED Mode
When bicolor LED mode is selected, the 3X38 provides two LED output signals per channel. These signals are the
activity LED outputs (BIACTLED) and the link LED outputs (BILINKLED). These two signals work together to drive
a single bicolor LED per channel; this is a single LED package with two LEDs connected in parallel with opposite
polarities. Typically, the BIACTLED is connected to the anode of a green LED with the cathode connected to the
BILINKLED output. A yellow LED is connected to the same outputs in the opposite polarity. The truth table is pro-
vided below.
Table 15. Bicolor Mode
BIACTLED
0
0
1
1
BILINKLED
0
1
0
1
Bicolor LED
State
Off
Green
Yellow
Off
Indicates
No link
Link up
Activity
Undefined
Activity pulse stretching and blinking can be used as described above, as well as forcing the LEDs on, off, or flash-
ing. To enable the bicolor LED forced mode, register 20, bit 10 must be written to a 1, and then register 20, bits 9
and 8 will be activated. When register 20, bit 9 is written to a 1 the BIACTLED (yellow) will flash 320 ms on, 320 ms
off. When register 20, bit 8 is written to a 1, the BILINKLED (green) will flash 320 ms on, 320 ms off. Other register
20 bits can be used to force these LEDs on or off. See register 20 description for details.
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Lucent Technologies Inc.