Hi,
i have 2 modules with W5300 chip in one rack, so they have equal power, reset timings and behavior.
Each W5300 chip is used in MACRAW mode.
I noticed no Link signal when they are directly connected after power on or system reset . This is a very often situation.
When connecting to switch or notebook Link is alway ok. Connecting them after other devices disconnection is also always ok.
I could solve this problem partly by applying a delay about 30 - 50 msec before hardware reset of w5300 chip on one of modules.
Hi,
schematic in attachment.
There are Bourns TBU protectors in tx, rx cirquits between RG connector and transformer (~10 Ohm resistance).
I tested with removed protectors. No changes in behavior.
After power on and reset when cable is unplugged on oscilloscope i can see autonegotiation Fast link pulses sequence 2 ms length with period of 16 ms. On tx and on rx pin (because of auto MDI/MDIX i think).
After this i connect second W5300 module with straight ethernet cable and after power on take an oscilloscope.
And now i can see second Fast link pulses sequence from the second W5300 module. Two sequences are synchronously
but shifted for ~1 msec so one sequense is partly covered by the other. And this shift is drifting until sequenses are not covered any more. This takes about 50 - 53 seconds. After this appears link signal.
Hi~
The circuit is no big issues. Have you ever Power-on-Reset did apply?
If you do not correctly Reset, the link may fail to occur. Reset secure a lot of time.
And if the link is successful late, Ethernet PHY fixed setting and testing.
Another way, the Ethernet line protection circuitry is removed and tested.
Thanks.