circuitpython/ports/raspberrypi/common-hal/floppyio/__init__.h
Jeff Epler 8e895e1986
Add floppyio for rp2040
Tested on RP2040 Feather with a 3.5" Prodigy diskette, the whole
surface reads 100% across 3+ trials.
2022-01-17 16:34:47 -06:00

38 lines
1.8 KiB
C

/*
* This file is part of the Micro Python project, http://micropython.org/
*
* The MIT License (MIT)
*
* Copyright (c) 2022 Jeff Epler for Adafruit Industries
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#pragma once
// empirical-ish from RP2040 @ 125MHz for floppy_flux_readinto
#define FLOPPYIO_SAMPLERATE (24000000)
// empirical-ish from RP2040 @ 125MHz for floppy_mfm_readinto
// my guess is these are slower because the more complex routine falls out of cache, but it's just
// speculation because the loops are very similar. When looking at raw bins with a modified
// version of adafruit_floppy, it can be seen that there are _two_ peaks for T2 and T3, rather
// than a single one, around 36 (mostly) and 43 (rarer), compared to a single peak around 48.
#define T2_5 (54)
#define T3_5 (75)