summaryrefslogtreecommitdiffstatshomepage
path: root/docs/library/machine.rst
diff options
context:
space:
mode:
Diffstat (limited to 'docs/library/machine.rst')
-rw-r--r--docs/library/machine.rst23
1 files changed, 18 insertions, 5 deletions
diff --git a/docs/library/machine.rst b/docs/library/machine.rst
index 7870da2ffc..753f6b4173 100644
--- a/docs/library/machine.rst
+++ b/docs/library/machine.rst
@@ -1,10 +1,23 @@
-:mod:`machine` --- functions related to the board
-=================================================
+:mod:`machine` --- functions related to the hardware
+====================================================
.. module:: machine
- :synopsis: functions related to the board
-
-The ``machine`` module contains specific functions related to the board.
+ :synopsis: functions related to the hardware
+
+The ``machine`` module contains specific functions related to the hardware
+on a particular board. Most functions in this module allow to achieve direct
+and unrestricted access to and control of hardware blocks on a system
+(like CPU, timers, buses, etc.). Used incorrectly, this can lead to
+malfunction, lockups, crashes of your board, and in extreme cases, hardware
+damage.
+
+.. _machine_callbacks:
+
+A note of callbacks used by functions and class methods of ``machine`` module:
+all these callbacks should be considered as executing in an interrupt context.
+This is true for both physical devices with IDs >= 0 and "virtual" devices
+with negative IDs like -1 (these "virtual" devices are still thin shims on
+top of real hardware and real hardware intrerrupts). See :ref:`isr_rules`.
Reset related functions
-----------------------