st802rt1a STMicroelectronics, st802rt1a Datasheet - Page 42

• Manufacturer Part Number: st802rt1a
• Description: 10/100 Real-time Ethernet 3.3 V Transceiver
• Manufacturer: STMicroelectronics

Device operation
7.11
Table 31.
Figure 6.
42/58
Mode
1
2
Write 0180h to RN12 to set INT_EN and INT_OE_N;
Write 0010h to RN12 to set LK_DWN_EN;
Monitor PWRDWN/MDINT.
When the PWRDWN/MDINT pin asserts low, the user should read the RN11 register to see
if the LK_DWN is set, i.e. which source caused the interrupt.
LED display operation
The ST802RT1x provides 3 LED pins.
operating modes, also described in
LED configuration
●
●
●
LED connections
RN1B[9]
1
0
Link LED: On when 100 M or 10 M link is active. It also blinks at 10 Hz for transmit and
receive.
Speed LED: 100 Mbps(on) or 10 Mbps(off)
Activity LED: Blinks at 20 Hz when there is a half-duplex activity on the media. It is
driven on continuously if full-duplex configuration is detected, or blinks when a collision
is detected.
BLINK for link-up + activity
OFF for no link
OFF for no link
ON for link-up
ON for link-up
LED link
Doc ID 17049 Rev 1
Table 4: Pin functions of the
Table 31
ON for 100Mb
OFF for 10Mb
ON for 100Mb
OFF for 10Mb
LED speed
contains a detailed description of the
ST802RT1x.
ST802RT1A, ST802RT1B
BLINK for collision
ON for full-duplex
BLINK for activity
LED act/col