STE100P_06 Datasheet, PDF (19/31 Pages) STMicroelectronics – 10/100 FAST ETHERNET 3.3V TRANSCEIVER

STE100P
Note:
The above LED connections are recommended for setting a Logic Level 1 or Logic Level 0 on the
STE100P LED/PHY Address pins, for determining PHY address.
7.11 Preamble Suppression
Preamble suppression mode in the STEPHY1 is indicated by a one in bit six of the PR1 Register. If it is
determined that all PHY devices in the system support preamble suppression, then a preamble is not nec-
essary for each management transaction. The first transaction following power-up/hardware reset re-
quires 32 bits of preamble. The full 32 bit preamble is not required for each additional transaction. The
STEPHY1 will respond to management accesses without preamble, but a minimum of one idle bit between
management transactions is required as specified in IEEE 802.3u.
7.12 Remote Fault
The remote fault function indicates to a link partner that a fault condition has occurred by using the Remote
Fault bit, which is encoded in bit 13 of the Link Code Word. A local device indicates to its link partner that
it has found a fault by setting the Remote Fault bit in the Auto-Negotiation register to logic one and rene-
gotiating with the link partner. The Remote Fault bit remains at logic one until successful negotiation with
the Link Code Word occurs. The bit will then return to 0. When the message is sent that the Remote Fault
bit is set to logic one, the device will set the Remote Fault bit in the MII to logic one if the management
function is present.
7.13 Transmit Isolation
Figure 7.
STA/STE
4/5
RxD
4/5
TxD
STEPHY1
Ethernet
ttp
tpn
MII
TX(100MHz)/TP(10MHz)
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