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Mity DSP-L138 Development board - 3 UARTS needed for final design?
Added by Angela Newman over 11 years ago
We are currently using your Mity DSP-L138 development board for software development until our own mother board is ready.
Our final design requires 3 UARTS - obviously UART1 and 2 are readily available on your board - but is there any way that we can get at UART0 - even if it means getting out a soldering iron?
Replies (1)
RE: Mity DSP-L138 Development board - 3 UARTS needed for final design? - Added by Michael Williamson over 11 years ago
I am assuming you are not using a MityDSP-L138F (with FPGA), right? If you do, I would simply put a UART into the FPGA...
If you are using a non-FPGA module, then you'll need to modify the PCB. It won't be trivial. There are schematics for the PCB here. If you need layout information, let me know.
To get at UART0, you'll need to disable ethernet in u-Boot as you'll need to re-assign the MII_RXD2 and MII_RXD3 lines to UART0_TXD (pin 81) and UART0_RXD (pin 83), respectively. Then you will need to break out a soldering iron and find a RS-232 driver and hack those pins to the driver. You'll also need to disconnect the lines from the connections on the TLK100 PHY on the development kit in order to avoid contention on the pins.
If you are running linux, you'll need to ensure that the pin-mux registers are updated to turn on UART0_TXD/RXD as well.
Hope this helps.
-Mike
