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== Packaging the Processor as IP block for Xilinx Vivado Block Designer

[start=1]
. Import all the core files from `rtl/core` (including default internal memory architectures from `rtl/core/mem`)
and assign them to a _new_ design library `neorv32`.
. Instantiate the `rtl/system_integration/neorv32_top_axi4lite.vhd` module.
. Then either directly use that module in a new block-design ("Create Block Design", right-click -> "Add Module",
thats easier for a first try) or package it ("Tools", "Create and Package new IP") for the use in other projects.
. Connect your AXI-peripheral directly to the core's AXI4-Interface if you only have one, or to an AXI-Interconnect
(from the IP-catalog) if you have multiple peripherals.
. Connect ALL the `ACLK` and `ARESETN` pins of all peripherals and interconnects to the processor's clock and reset
signals to have a _unified_ clock and reset domain (easier for a first setup).
. Open the "Address Editor" tab and let Vivado assign the base-addresses for the AXI-peripherals (you can modify them
according to your needs).
. For all FPGA-external signals (like UART signals) make all the connections you need "external"
(right-click on the signal/pin -> "Make External").
. Save everything, let VIVADO create a HDL-Wrapper for the block-design and choose this as your _Top Level Design_.
. Define your constraints and generate your bitstream.

.Example AXI SoC using Xilinx Vivado
image::neorv32_axi_soc.png[]

.True Random Number Generator
[IMPORTANT]
The NEORV32 TRNG peripheral is enabled by default in the `neorv32_top_axi4lite` AXI wrapper. Otherwise, Vivado
cannot insert the wrapper into a block design (see https://github.com/stnolting/neorv32/issues/227.).
footnote:[Seems like Vivado has problem evaluating design source files that have more than two in-file sub-entities.]
If the TRNG is not needed, you can disable it by double-clicking on the module's block and de-selecting
"IO_TRNG_EN" after inserting the module.

**Combinatorial Loops DRC error**
If the TRNG is enabled it is recommended to add the following commands to the project's constraints file in order
to prevent DRC errors during bitstream generation:

[source,xdc]
----
set_property SEVERITY {warning} [get_drc_checks LUTLP-1]
set_property IS_ENABLED FALSE [get_drc_checks LUTLP-1]
set_property ALLOW_COMBINATORIAL_LOOPS TRUE
----

[NOTE]
Guide provided by GitHub user https://github.com/AWenzel83[`AWenzel83`] (see
https://github.com/stnolting/neorv32/discussions/52#discussioncomment-819013). ❤️
