AnsweredAssumed Answered

STM32F429I-DISCO LCD and ETHERNET CONFLICT

Question asked by gore.mike on Dec 30, 2013
Latest reply on Feb 11, 2014 by gore.mike
I think I found a serious pin conflict with the CPU being used on the STM32F429I-DISCO boards if you want use the TFT LCD and networking at the same time.

The TFT LCD interface function conflicts with the only two possible alternate function options for ETH_RM11_TX_EN pin (needed if you want a RMII network interface - its worse if you want an MII interface)
Specifically PG11 conflicts with DB1/B3 on the LCD_TFT interface
and PB11 conflicts with DB9/G5 of the LCD_TFT interface.
There are no other alternates for the ETH_RM11_TX_EN pin!
The remaining conflicts with the USB interface: OTG_FS_PSO, OTG_FS_OC, the L3GD20 device: INT1,INT2,CS - can all be worked around - but the ETH_RMII_TX_EN issue seems to be a show stopper.
If you want a TFT/RGB display - you can not have a network.

So much for an internet connected system with a display - this appears to be a CPU limitation by design ? Am I wrong ?

My question is why did the designers do this when there were other free pins ? Is there any other option for using the DISPLAY and the RMII network transceiver ?

Outcomes