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docs/uctypes: Fix API description errors.

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"Structure class" is its descriptor, encoded as a dictionary. Then,
uctypes.struct() instantiates an actual object, and thus requires memory
address.
This commit is contained in:
Paul Sokolovsky 2015-06-02 10:30:01 +03:00
parent 0df20da4dd
commit f8bce131c0
1 changed files with 10 additions and 9 deletions
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19
docs/library/uctypes.rst
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@ -96,10 +96,11 @@ Following are encoding examples for various field types:
Module contents
---------------
.. class:: struct(descriptor, layout_type)
.. class:: struct(descriptor, addr, layout_type-NATIVE)
Create a "foreign data structure" class based on its descriptor (encoded
as a dictionary) and layout type (see below).
Instantiate a "foreign data structure" object based on structure descriptor
(encoded as a dictionary), layout type (see below), and actual structure
address.
.. data:: LITTLE_ENDIAN
@ -140,16 +141,16 @@ Module contents
so it can be both written too, and you will access current value
at the given memory address.
Structure classes and instantiating structure objects
Structure descriptors and instantiating structure objects
-----------------------------------------------------
Given structure descriptor and layout type, you can instantiate a
"structure class" using uctypes.struct() factory function. From it,
you can instantiate a specific structure instance at a given
memory address. Memory address usually comes from following sources:
Given a structure descriptor dictionary and its layout type, you can
instantiate a specific structure instance at a given memory address
using uctypes.struct() constructor. Memory address usually comes from
following sources:
* Predefined address, when accessing hardware registers on a baremetal
port. Lookup these addresses in datasheet for a particular MCU/SoC.
system. Lookup these addresses in datasheet for a particular MCU/SoC.
* As return value from a call to some FFI (Foreign Function Interface)
function.
* From uctypes.addressof(), when you want to pass arguments to FFI