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Altera_Forum's avatar
Altera_Forum
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10 years ago

Loan I/O DE1-SoC UART0

I am trying to use LOAN I/O to steal HPS UART0 RX/RX for use in my FPGA logic. I.e I have an VHDL UART that I want to connect to UART0 RX/TX pins. Is this possible?

I have read this post: http://www.alteraforum.com/forum/showthread.php?t=44486&highlight=loan+io

And it seems possible. However, in simulation I get no "connection" between HPS_UART_RX and the loaned port. I have setup loan_io_oe (i.e. '1' when output).

This got me thinking (from https://www.altera.com/en_us/pdfs/literature/hb/cyclone-v/cv_5v4.pdf):

the loanio only operates when the hps registers have been set up in the pre-loader to allowtheir operation.

bsp-editor has no checkboxes or options regarding LoanIO.

I am confused, hope someone can clarify.

1 Reply

  • Altera_Forum's avatar
    Altera_Forum
    Icon for Honored Contributor rankHonored Contributor
    10 years ago

    1) bsp-editor will automatically generate preloader code according to HPS settings in QSYS. ( for example, the GPIO65 set as LoadIO65)

    2) HPS pin mux has assigned after preloader running.

    3) I think the "loan IO" can't do simulation.