mac-rom-simm-programmer/hal/at90usb646/Descriptors.h
Doug Brown 7425af761a Break out code into a HAL, optimize flash operations
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.
2020-11-27 00:16:35 -08:00

90 lines
3.3 KiB
C

/*
LUFA Library
Copyright (C) Dean Camera, 2011.
dean [at] fourwalledcubicle [dot] com
www.lufa-lib.org
*/
/*
Copyright 2011 Dean Camera (dean [at] fourwalledcubicle [dot] com)
Permission to use, copy, modify, distribute, and sell this
software and its documentation for any purpose is hereby granted
without fee, provided that the above copyright notice appear in
all copies and that both that the copyright notice and this
permission notice and warranty disclaimer appear in supporting
documentation, and that the name of the author not be used in
advertising or publicity pertaining to distribution of the
software without specific, written prior permission.
The author disclaim all warranties with regard to this
software, including all implied warranties of merchantability
and fitness. In no event shall the author be liable for any
special, indirect or consequential damages or any damages
whatsoever resulting from loss of use, data or profits, whether
in an action of contract, negligence or other tortious action,
arising out of or in connection with the use or performance of
this software.
*/
/** \file
*
* Header file for Descriptors.c.
*/
#ifndef _DESCRIPTORS_H_
#define _DESCRIPTORS_H_
/* Includes: */
#include <avr/pgmspace.h>
#include "LUFA/Drivers/USB/USB.h"
/* Macros: */
/** Endpoint number of the CDC device-to-host notification IN endpoint. */
#define CDC_NOTIFICATION_EPNUM 2
/** Endpoint number of the CDC device-to-host data IN endpoint. */
#define CDC_TX_EPNUM 3
/** Endpoint number of the CDC host-to-device data OUT endpoint. */
#define CDC_RX_EPNUM 4
/** Size in bytes of the CDC device-to-host notification IN endpoint. */
#define CDC_NOTIFICATION_EPSIZE 8
/** Size in bytes of the CDC data IN and OUT endpoints. */
#define CDC_TXRX_EPSIZE 64
/* Type Defines: */
/** Type define for the device configuration descriptor structure. This must be defined in the
* application code, as the configuration descriptor contains several sub-descriptors which
* vary between devices, and which describe the device's usage to the host.
*/
typedef struct
{
USB_Descriptor_Configuration_Header_t Config;
// CDC Command Interface
USB_Descriptor_Interface_t CDC_CCI_Interface;
USB_CDC_Descriptor_FunctionalHeader_t CDC_Functional_Header;
USB_CDC_Descriptor_FunctionalACM_t CDC_Functional_ACM;
USB_CDC_Descriptor_FunctionalUnion_t CDC_Functional_Union;
USB_Descriptor_Endpoint_t CDC_NotificationEndpoint;
// CDC Data Interface
USB_Descriptor_Interface_t CDC_DCI_Interface;
USB_Descriptor_Endpoint_t CDC_DataOutEndpoint;
USB_Descriptor_Endpoint_t CDC_DataInEndpoint;
} USB_Descriptor_Configuration_t;
/* Function Prototypes: */
uint16_t CALLBACK_USB_GetDescriptor(const uint16_t wValue,
const uint8_t wIndex,
const void** const DescriptorAddress)
ATTR_WARN_UNUSED_RESULT ATTR_NON_NULL_PTR_ARG(3);
#endif