IO Standard and Pin Definition on ZC702

Question

Hi,
I am currently working with a ZC702 eval board using a Microblaze processor with UART to run a "Hello World" program to a terminal. I have run Connection Automation and Block Automation but when I run generate bitstream I receive User Assigned constraint and IO Standard errors.
The problem ports are specifically the reset, rs232_uart_rxd, and rs232_uart_txd. I know the UART pins are defined as C14 and D11 in the user manual but these pins are not available in the IO planner and I chose to assign the reset signal to a pushbutton on B5.
Is there a reason why I can't assign these signals to their respective pins? They are not available to assign any signal to them at all, they are labeled as "Read Only".
I inserted a screenshot of the block design for the project.

Answer 1

n,
There is the processor system (PS), and the programmable logic (PL) in Zynq.
The PS has its own IO pins, specifically for PS functions.
The PL has its own IO pins, as part of the IOB tiles, in the programmble logic fabric.
The signals:  reset, rs232_uart_rxd, and rs232_uart_txd -- they are the PS signals (not PL signals).  So they are not availble to be used by the PL.  You will have to choose PL IO pins to carry these signals.  That may be quite incovenient, as the uart signals will need to go to a RS232C level shifter, USB converter, or some other terminal interface, which may not be present on the ZC702 pcb (in fact, it is not).  There is the FMC connector for PL IO, so you may need  a FMC adapter board.  I see no boards that provide a UART-USB connection, however.
Refer to ug850 to see what is PL, and what is PS in terms of IO.