| Line 13... |
Line 13... |
| | _MEM_INT_IMEM_SIZE_ | IMEM size in bytes
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| | _MEM_INT_IMEM_SIZE_ | IMEM size in bytes
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| | _INT_BOOTLOADER_EN_ | use internal bootloader when _true_ (implements IMEM as _uninitialized_ RAM)
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| | _INT_BOOTLOADER_EN_ | use internal bootloader when _true_ (implements IMEM as _uninitialized_ RAM)
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| CPU interrupts: | none |
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| CPU interrupts: | none |
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|=======================
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|=======================
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[NOTE]
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The actual IMEM is split into two design files: a plain entity definition (`neorv32_imem.entity.vhd`) and the actual
|
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architecture definition (`mem/neorv32_imem.default.vhd`). This **default architecture** provides a _generic_ and
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_platform independent_ memory design that (should) infers embedded memory block. You can replace/modify the architecture
|
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source file in order to use platform-specific features (like advanced memory resources) or to improve technology mapping
|
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and/or timing.
|
|
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Implementation of the processor-internal instruction memory is enabled via the processor's
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Implementation of the processor-internal instruction memory is enabled via the processor's
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_MEM_INT_IMEM_EN_ generic. The size in bytes is defined via the _MEM_INT_IMEM_SIZE_ generic. If the
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_MEM_INT_IMEM_EN_ generic. The size in bytes is defined via the _MEM_INT_IMEM_SIZE_ generic. If the
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IMEM is implemented, the memory is mapped into the instruction memory space and located right at the
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IMEM is implemented, the memory is mapped into the instruction memory space and located right at the
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beginning of the instruction memory space (default `ispace_base_c` = 0x00000000).
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beginning of the instruction memory space (default `ispace_base_c` = 0x00000000).
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By default, the IMEM is implemented as RAM, so the content can be modified during run time. This is
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By default the IMEM is implemented as true RAM so the content can be modified during run time. This is
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required when using a bootloader that can update the content of the IMEM at any time. If you do not need
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required when using a bootloader that can update the content of the IMEM at any time. If you do not need
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the bootloader anymore - since your application development has completed and you want the program to
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the bootloader anymore - since your application development has completed and you want the program to
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permanently reside in the internal instruction memory - the IMEM is automatically implemented as _pre-intialized_
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permanently reside in the internal instruction memory - the IMEM is automatically implemented as _pre-intialized_
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ROM when the processor-internal bootloader is disabled (_INT_BOOTLOADER_EN_ = _false_).
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ROM when the processor-internal bootloader is disabled (_INT_BOOTLOADER_EN_ = _false_).
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When the IMEM is implemented as ROM, it will be initialized during synthesis with the actual application
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When the IMEM is implemented as ROM, it will be initialized during synthesis (actually, by the bitstream)
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program image. The compiler toolchain will generate a VHDL initialization
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with the actual application program image. The compiler toolchain will generate a VHDL initialization
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file `rtl/core/neorv32_application_image.vhd`, which is automatically inserted into the IMEM. If
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file `rtl/core/neorv32_application_image.vhd`, which is automatically inserted into the IMEM. If
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the IMEM is implemented as RAM (default), the memory will **not be initialized** at all.
|
the IMEM is implemented as RAM (default), the memory will **not be initialized at all**.
|
|
|
|
[NOTE]
|
|
The actual IMEM is split into two design files: a plain entity definition (`neorv32_imem.entity.vhd`) and the actual
|
|
architecture definition (`mem/neorv32_imem.default.vhd`). This **default architecture** provides a _generic_ and
|
|
_platform independent_ memory design that (should) infers embedded memory block. You can replace/modify the architecture
|
|
source file in order to use platform-specific features (like advanced memory resources) or to improve technology mapping
|
|
and/or timing.
|
