.. _max3421e_shield:

MAX3421E Shield
###############

Overview
********

Support for expansion boards (shields) based on MAX3421E USB Peripheral/Host
controller.

Sparkfun USB Host Shield
************************

Pins Assignment of the Shield Connector
=======================================

+-----------------------+-----------------------+-----------------------------+
| Shield Connector Pin  | Function              | MAX3421E Pin                |
+=======================+=======================+=============================+
| D0                    | not connected         |                             |
+-----------------------+-----------------------+-----------------------------+
| D1                    | not connected         |                             |
+-----------------------+-----------------------+-----------------------------+
| D2                    | not connected         |                             |
+-----------------------+-----------------------+-----------------------------+
| D3                    | not connected         |                             |
+-----------------------+-----------------------+-----------------------------+
| D4                    | not connected         |                             |
+-----------------------+-----------------------+-----------------------------+
| D5                    | not connected         |                             |
+-----------------------+-----------------------+-----------------------------+
| D6                    | not connected         |                             |
+-----------------------+-----------------------+-----------------------------+
| D7                    | RESET pin             |                             |
+-----------------------+-----------------------+-----------------------------+
| D8                    | not connected         |                             |
+-----------------------+-----------------------+-----------------------------+
| D9                    | INTn                  | 24 (Interrupt Output)       |
+-----------------------+-----------------------+-----------------------------+
| D10                   | SPI CSn               | 34 (SPI Chip Select)        |
+-----------------------+-----------------------+-----------------------------+
| D11                   | SPI MOSI              | 36 (SPI Serial Data Input)  |
+-----------------------+-----------------------+-----------------------------+
| D12                   | SPI MISO              | 35 (SPI Serial Data Out)    |
+-----------------------+-----------------------+-----------------------------+
| D13                   | SPI SCK               | 37 (SPI Serial Clock Input) |
+-----------------------+-----------------------+-----------------------------+
| D14                   | not connected         |                             |
+-----------------------+-----------------------+-----------------------------+
| D15                   | not connected         |                             |
+-----------------------+-----------------------+-----------------------------+

Programming
***********

Set ``-DSHIELD=sparkfun_max3421e`` when you invoke ``west build`` or ``cmake``
in your Zephyr application.