Forum Discussion

jrodr29's avatar
jrodr29
Icon for New Contributor rankNew Contributor
6 years ago

DE1-SoC: FT UART starts transmitting invalid data after cable is plugged.

I am connecting UART to FPGA through io loaning.

UART_RX data is reaching the FPGA,

but serial data transmitted by FPGA is not going through.

UART is only sending bits after cable is connected, or remote terminal starts session.

[ I have disabled any performance/printf configuration in the preloader ]

[ and confirmed RTL connection int the viewer ]

[The baud rate specified in the FT driver is matched with the terminal as well]

Any hints?

2 Replies

  • jrodr29's avatar
    jrodr29
    Icon for New Contributor rankNew Contributor

    One step forward : baudrate must be set up to 115200, and I start getting below data;

    now : how to stop it and get the TX for the FPGA ...???

    < ---

    U-Boot SPL 2013.01.01 (Aug 17 2016 - 15:27:26)

    BOARD : Altera SOCFPGA Cyclone V Board

    CLOCK: EOSC1 clock 25000 KHz

    CLOCK: EOSC2 clock 25000 KHz

    CLOCK: F2S_SDR_REF clock 0 KHz

    CLOCK: F2S_PER_REF clock 0 KHz

    CLOCK: MPU clock 800 MHz

    CLOCK: DDR clock 400 MHz

    CLOCK: UART clock 100000 KHz

    CLOCK: MMC clock 50000 KHz

    CLOCK: QSPI clock 400000 KHz

    RESET: WARM

    -->

    INFO : Watchdog enabled

    SDRAM: Initializing MMR registers

    SDRAM: Calibrating PHY

    SEQ.C: Preparing to start memory calibration

    SEQ.C: CALIBRATION PASSED

    SDRAM: 1024 MiB

    ALTERA DWMMC: 0

    -->

  • FawazJ_Altera's avatar
    FawazJ_Altera
    Icon for Frequent Contributor rankFrequent Contributor
    Hello, Not clear where are you connecting this UART. Is it connected to HPS? because thats what I can see from the above messages. if it is connected to HPS, then you cannot use any internal source of FPGA to use this UART terminal. usually we have two terminals, one is through UART to HSP, and one through JTAG UART to FPGA. Thanks