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7425af761a
This makes the code pretty easily portable to other architectures if someone wants to make a more modern SIMM programmer. I also was pretty careful to split responsibilities of the different components and give the existing components better names. I'm pretty happy with the organization of the code now. As part of this change I have also heavily optimized the code. In particular, the read and write cycle routines are very important to the overall performance of the programmer. In these routines I had to make some tradeoffs of code performance versus prettiness, but the overall result is much faster programming. Some of these performance changes are the result of what I discovered when I upgraded my AVR compiler. I discovered that it is smarter at looking at 32-bit variables when I use a union instead of bitwise operations. I also shaved off more CPU cycles by carefully making a few small tweaks. I added a bypass for the "program only some chips" mask, because it was adding unnecessary CPU cycles for a feature that is rarely used. I removed the verification feature from the write routine, because we can always verify the data after the write chunk is complete, which is more efficient. I also added assumptions about the initial/final state of the CS/OE/WE pins, which allowed me to remove more valuable CPU cycles from the read/write cycle routines. There are also a few enormous performance optimizations I should have done a long time ago: 1) The code was only handling one received byte per main loop iteration. Reading every byte available cut nearly a minute off of the 8 MB programming time. 2) The code wasn't taking advantage of the faster programming command available in the chips used on the 8 MB SIMM. The end result of all of these optimizations is I have programming time of the 8 MB SIMM down to 3:31 (it used to be 8:43). Another minor issue I fixed: the Micron SIMM chip identification wasn't working properly. It was outputting the manufacturer ID again instead of the device ID.
101 lines
3.6 KiB
C
101 lines
3.6 KiB
C
/*
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LUFA Library
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Copyright (C) Dean Camera, 2012.
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dean [at] fourwalledcubicle [dot] com
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www.lufa-lib.org
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*/
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/*
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Copyright 2012 Dean Camera (dean [at] fourwalledcubicle [dot] com)
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Permission to use, copy, modify, distribute, and sell this
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software and its documentation for any purpose is hereby granted
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without fee, provided that the above copyright notice appear in
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all copies and that both that the copyright notice and this
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permission notice and warranty disclaimer appear in supporting
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documentation, and that the name of the author not be used in
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advertising or publicity pertaining to distribution of the
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software without specific, written prior permission.
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The author disclaim all warranties with regard to this
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software, including all implied warranties of merchantability
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and fitness. In no event shall the author be liable for any
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special, indirect or consequential damages or any damages
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whatsoever resulting from loss of use, data or profits, whether
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in an action of contract, negligence or other tortious action,
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arising out of or in connection with the use or performance of
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this software.
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*/
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/*
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This is a stub driver header file, for implementing custom board
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layout hardware with compatible LUFA board specific drivers. If
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the library is configured to use the BOARD_USER board mode, this
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driver file should be completed and copied into the "/Board/" folder
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inside the application's folder.
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This stub is for the board-specific component of the LUFA Joystick
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driver, for a digital four-way (plus button) joystick.
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*/
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#ifndef __JOYSTICK_USER_H__
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#define __JOYSTICK_USER_H__
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/* Includes: */
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// TODO: Add any required includes here
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/* Enable C linkage for C++ Compilers: */
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#if defined(__cplusplus)
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extern "C" {
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#endif
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/* Preprocessor Checks: */
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#if !defined(__INCLUDE_FROM_JOYSTICK_H)
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#error Do not include this file directly. Include LUFA/Drivers/Board/Joystick.h instead.
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#endif
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/* Public Interface - May be used in end-application: */
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/* Macros: */
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/** Mask for the joystick being pushed in the left direction. */
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#define JOY_LEFT // TODO: Add mask to indicate joystick left position here
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/** Mask for the joystick being pushed in the right direction. */
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#define JOY_RIGHT // TODO: Add mask to indicate joystick right position here
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/** Mask for the joystick being pushed in the upward direction. */
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#define JOY_UP // TODO: Add mask to indicate joystick up position here
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/** Mask for the joystick being pushed in the downward direction. */
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#define JOY_DOWN // TODO: Add mask to indicate joystick down position here
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/** Mask for the joystick being pushed inward. */
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#define JOY_PRESS // TODO: Add mask to indicate joystick pressed position here
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/* Inline Functions: */
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#if !defined(__DOXYGEN__)
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static inline void Joystick_Init(void)
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{
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// TODO: Initialize joystick port pins as inputs with pull-ups
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}
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static inline void Joystick_Disable(void)
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{
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// TODO: Clear the joystick pins as high impedance inputs here
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}
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static inline uint8_t Joystick_GetStatus(void) ATTR_WARN_UNUSED_RESULT;
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static inline uint8_t Joystick_GetStatus(void)
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{
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// TODO: Return current joystick position data which can be obtained by masking against the JOY_* macros
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}
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#endif
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/* Disable C linkage for C++ Compilers: */
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#if defined(__cplusplus)
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}
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#endif
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#endif
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