Overview and Warning:
This library was originally created to experiement with the FlexIO capabilities of the new Teensy 4 board and will also support the Teensy 4.1
This program is free software: you can redistribute it and/or modify it
This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
Details on FlexIO
See chapter 49 of the IMXRT1060RM manual which you can download from the PJRC website: https://www.pjrc.com/teensy/datasheets.html
There are more discussions about FlexIO up on the PJRC forum, including: https://forum.pjrc.com/threads/58228-T4-FlexIO-Looking-back-at-my-T4-beta-testing-library-FlexIO_t4
FlexIO pins on T4 and T4.1
The Teensy 4. has the following Flex IO pins defined:
Note: I have these tables in Teensy pin number order, It may also be interesting to also have a version with FlexIO pin order, as at some point I will experiment with parallel pin IO..
FlexIO 1 - The three rows are: Teensy pin, Flex IO pin, and MUX setting for that pin:
2, 3, 4, 5, 33,
4, 5, 6, 8, 7,
0x14, 0x14, 0x14, 0x14, 0x14
FlexIO 2
6, 7, 8, 9, 10, 11, 12, 13, 32,
10, 17, 16, 11, 0, 2, 1, 3, 12,
0x14, 0x14, 0x14, 0x14, 0x14, 0x14, 0x14, 0x14, 0x14,
FlexIO 3 - Note Flex IO 3 does not have DMA support
7, 8, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 26, 27,
17, 16, 2, 3, 7, 6, 1, 0, 10, 11, 8, 9, 14, 15,
0x19, 0x19, 0x19, 0x19, 0x19, 0x19, 0x19, 0x19, 0x19, 0x19, 0x19, 0x19, 0x19, 0x19,
The Teensy 4.1 Will have additional IO pins.
Warning The below now matches the first update to github CORE project for T4.1 by Paul, so the final pin numbers are probably reasonably close, but probably not written in stone until the boards actually start shipping. So maybe take it with grain of salt.
FlexIO 1 - The three rows are: Teensy pin, Flex IO pin, and MUX setting for that pin:
2, 3, 4, 5, 33, 49, 50, 52, 54
4, 5, 6, 8, 7, 13, 14, 12, 15
0x14, 0x14, 0x14, 0x14, 0x14, 0x14, 0x14, 0x14, 0x14
Ranges: 4-8,12-15
FlexIO 2
6, 7, 8, 9, 10, 11, 12, 13, 32, 34, 35, 36, 37
10, 17, 16, 11, 0, 2, 1, 3, 12, 29, 28, 18, 19
0x14, 0x14, 0x14, 0x14, 0x14, 0x14, 0x14, 0x14, 0x14, 0x14, 0x14, 0x14, 0x14
So have bit ranges 0-3, 10-12, 16-19, 28029
FlexIO 3 - Note Flex IO 3 does not have DMA support
7, 8, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 26, 27, 34, 35, 36, 37, 38, 39, 40, 41
17, 16, 2, 3, 7, 6, 1, 0, 10, 11, 8, 9, 14, 15, 29, 28, 18, 19, 12, 13, 4, 5
0x19, 0x19, 0x19, 0x19, 0x19, 0x19, 0x19, 0x19, 0x19, 0x19, 0x19, 0x19, 0x19, 0x19, 0x19, 0x19, 0x19, 0x19, 0x19, 0x19, 0x19, 0x19
Have ranges: 0-19, 28-29