to se mi zdá jako blbost. Koukal si někdy na tu techniku kodování fast/gigo ethernetu? v signálu jsou zakodováný hodiny. Problěm spíš bude v kabelu nebo konektorech potažmo špatných kontaktech.
ke spatnym kabelum - znovu - nedokazu si vysvetlit jak by ty chyby mohly zmizet po zmene nastaveni ALCOMY na Slave
spravne v signalu jsou hodiny. Akorat si nejsem jisty, zda nejsou jen tesne pred vlasnimi daty kde se vysilanejaka synchronizacni sekvence (tohle jsem nestudoval). Pro me je smerodatny , ze v IEEE norme pro gigo se pise, ze Slave synchronizuje sve hodiny podle toho, co vysila Master.
40.1.3
...
A 1000BASE-T PHY can be configured either as a MASTER PHY or as a SLAVE PHY. The MASTER-
SLAVE relationship between two stations sharing a link segment is established during Auto-
Negotiation (see Clause 28, 40.5, and Annex 28C). The MASTER PHY uses a local clock to determine the
timing of transmitter operations. The SLAVE PHY recovers the clock from the received signal and uses it to
determine the timing of transmitter operations, i.e., it performs loop timing, as illustrated in Figure 40-3. In a
multiport to single-port connection, the multiport device is typically set to be MASTER and the single-port
device is set to be SLAVE.
40.4.2.6 Clock Recovery function
The Clock Recovery function couples to all four receive pairs. It may provide independent clock phases for
sampling the signals on each of the four pairs.
The Clock Recovery function shall provide clocks suitable for signal sampling on each line so that the symbol-
error rate indicated in 40.4.2.3 is achieved. The received clock signal must be stable and ready for use
when training has been completed (loc_rcvr_status=OK). The received clock signal is supplied to the PMA
Transmit function by received_clock.
pak je třeba se zeptat proč se tohle děje pouze u pojítek tohodle typu. I orcave má sem tam s timhle problem nebo aspoň starší typy měly.
