32 lines
1.1 KiB
ReStructuredText
32 lines
1.1 KiB
ReStructuredText
AMBA 4 APB
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==========
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Implements the register block using an
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`AMBA 4 APB <https://developer.arm.com/documentation/ihi0024/d/?lang=en>`_
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CPU interface.
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The APB4 CPU interface comes in two i/o port flavors:
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SystemVerilog Interface
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Class: :class:`peakrdl_regblock.cpuif.apb4.APB4_Cpuif`
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Interface Definition: :download:`apb4_intf.sv <../../tests/lib/cpuifs/apb4/apb4_intf.sv>`
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Flattened inputs/outputs
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Flattens the interface into discrete input and output ports.
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Class: :class:`peakrdl_regblock.cpuif.apb4.APB4_Cpuif_flattened`
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.. warning::
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Some IP vendors will incorrectly implement the address signalling
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assuming word-addresses. (that each increment of ``PADDR`` is the next word)
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For this exporter, values on the interface's ``PADDR`` input are interpreted
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as byte-addresses. (a 32-bit APB bus increments ``PADDR`` in steps of 4)
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Although APB protocol does not allow for unaligned transfers, this is in
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accordance to the official AMBA bus specification.
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Be sure to double-check the interpretation of your interconnect IP. A simple
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bit-shift operation can be used to correct this if necessary.
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