mirror of
https://github.com/dougg3/mac-rom-simm-programmer.git
synced 2025-01-03 21:31:44 +00:00
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.
28 lines
1.7 KiB
Plaintext
28 lines
1.7 KiB
Plaintext
/** \file
|
|
*
|
|
* This file contains special DoxyGen information for the generation of the main page and other special
|
|
* documentation pages. It is not a project source file.
|
|
*/
|
|
|
|
/** \page Page_GettingStarted Getting Started
|
|
*
|
|
* Out of the box, LUFA contains a large number of pre-made class demos for you to test, experiment with and
|
|
* ultimately build upon for your own projects. All the demos (where possible) come pre-configured to build and
|
|
* run correctly on the AT90USB1287 AVR microcontroller, mounted on the Atmel USBKEY board and running at an 8MHz
|
|
* master clock. This is due to two reasons; one, it is the hardware the author possesses, and two, it is the most
|
|
* popular Atmel USB demonstration board to date. To learn how to reconfigure, recompile and program the included
|
|
* LUFA applications using different settings, see the subsections below.
|
|
*
|
|
* Most of the included demos in the /Demos/ folder come in both ClassDriver and LowLevel varieties. If you are new
|
|
* to LUFA, it is highly recommended that you look at the ClassDriver versions first, which use the pre-made USB
|
|
* Class Drivers (\ref Group_USBClassDrivers) to simplify the use of the standard USB classes in user applications.
|
|
*
|
|
* For an overview of the included library applications, bootloaders and demos, see \ref Page_LibraryApps.
|
|
*
|
|
* <b>Subsections:</b>
|
|
* \li \subpage Page_ConfiguringApps - How to Configure the Included Demos, Projects and Bootloaders
|
|
* \li \subpage Page_CompilingApps - How to Compile the Included Demos, Projects and Bootloaders
|
|
* \li \subpage Page_ProgrammingApps - How to Program an AVR with the Included Demos, Projects and Bootloaders
|
|
*/
|
|
|