Subversion Repositories neorv32

# Test Setups

This folder contains very simple test setups that are intended for project beginners
to setup a minimal NEORV32 SoC. These setups are used in the :books:
[NEORV32 User Guide](https://stnolting.github.io/neorv32/ug/).
Note that these setups provides a minimalistic configuration to keep
things at a simple level at first. Additional CPU ISA extensions, performance options and
optional peripheral modules can be enabled by specifying the according :book:
[configuration generics](https://stnolting.github.io/neorv32/#_processor_top_entity_generics).


### Setup's Top Entity

#### Clocking and Reset

All test setups require an external clock (via `clk_i` signal) and an external
low-active reset (via `rstn_i` signal).

#### Configuration Generics

Each setup provides three elementary generics that can/should be adapted to fit
your FPGA/board.

* The clock speed in Hz **has to be specified** via the `CLOCK_SPEED` generic to fit your clock source.
* The processor-internal instruction memory (IMEM) size _can be modified_ via the `MEM_INT_IMEM_SIZE` generic.
* The processor-internal data memory (DMEM) size _can be modified_ via the `MEM_INT_DMEM_SIZE` generic.
Note that this might require adaption of the NEORV32 linker script.


### [`neorv32_test_setup_approm.vhd`](https://github.com/stnolting/neorv32/blob/main/rtl/test_setups/neorv32_test_setup_approm.vhd)

This setup configures a `rv32imc_Zicsr` CPU with 16kB IMEM (as pre-initialized ROM),
8kB DMEM and includes the GPIO module to drive 8 external signals (`gpio_o`)
and the MTIME module for generating timer interrupts.
The setup uses the ["indirect boot"](https://stnolting.github.io/neorv32/#_indirect_boot)
configuration, so software applications are "installed" directly into the
processor-internal IMEM during synthesis.

:books: See User Guide section [_Installing an Executable Directly Into Memory_](https://stnolting.github.io/neorv32/ug/#_installing_an_executable_directly_into_memory).


### [`neorv32_test_setup_bootloader.vhd`](https://github.com/stnolting/neorv32/blob/main/rtl/test_setups/neorv32_test_setup_bootloader.vhd)

This setup configures a `rv32imc_Zicsr` CPU with 16kB IMEM (as RAM), 8kB DMEM
and includes the GPIO module to drive 8 external signals (`gpio_o`), the MTIME
module for generating timer interrupts and UART0 to interface with the bootloader
(via `uart0_txd_o` and `uart0_rxd_i`) via a serial terminal.
The setup uses the ["direct boot"](https://stnolting.github.io/neorv32/#_direct_boot)
configuration, so software applications can be uploaded and run at any timer via a serial terminal.

:books: See User Guide section
[_Uploading and Starting of a Binary Executable Image via UART_](https://stnolting.github.io/neorv32/ug/#_uploading_and_starting_of_a_binary_executable_image_via_uart).