We use w5300 chip in our project and have a problem that connection is often lost when bus is used.
In our system we have MCU(master) SRAM, FPGA, W5300 sharing the same bus.
Chip Select and OutputEnable(aka Read signal) are multiplexed to communicate with each device separately.
W5300 is connected with 8bit data and full address bus. FPGA is connected with multiplexed bus mode where address bus is combined with data bus.
Everything works fine separately, W5300 is initialized and data transmission is ok, but when MCU starts to read FPGA Ethernet chip connection sometimes is lost for about half second. I say sometimes because it happens not all the time. may be once in 100 readings, but when we read a big sequence of data it happens almost all the time.
W5300 Shares only 10 address bit and WriteEnable line with FPGA. Ethernet CS, OE, reset and int pins does not change its value when connection lost happens. WE is also stay high without changes when this happen.
Can anybody explain or give idea what is wrong? As I understand if W5300 CS is high(unselected) address bus can have any values without affecting chip.