diff options
Diffstat (limited to 'docs/esp32')
| -rw-r--r-- | docs/esp32/quickref.rst | 11 |
1 files changed, 9 insertions, 2 deletions
diff --git a/docs/esp32/quickref.rst b/docs/esp32/quickref.rst index 5ac8aa3b2f..76fe0d9f9e 100644 --- a/docs/esp32/quickref.rst +++ b/docs/esp32/quickref.rst @@ -128,6 +128,8 @@ with timer ID of -1:: The period is in milliseconds. +.. _Pins_and_GPIO: + Pins and GPIO ------------- @@ -274,8 +276,13 @@ class:: Hardware SPI bus ---------------- -There are two hardware SPI channels that allow faster (up to 80Mhz) -transmission rates, but are only supported on a subset of pins. +There are two hardware SPI channels that allow faster transmission +rates (up to 80Mhz). These may be used on any IO pins that support the +required direction and are otherwise unused (see :ref:`Pins_and_GPIO`) +but if they are not configured to their default pins then they need to +pass through an extra layer of GPIO multiplexing, which can impact +their reliability at high speeds. Hardware SPI channels are limited +to 40MHz when used on pins other than the default ones listed below. ===== =========== ============ \ HSPI (id=1) VSPI (id=2) |