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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.
52 lines
1.4 KiB
C
52 lines
1.4 KiB
C
/*
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* usbcdc_hw.h
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*
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* Created on: Nov 22, 2020
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* Author: Doug
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*/
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#ifndef HAL_AT90USB646_USBCDC_HW_H_
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#define HAL_AT90USB646_USBCDC_HW_H_
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#include "LUFA/Drivers/USB/USB.h"
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#include "cdc_device_definition.h"
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/** Sends a byte over the USB CDC serial port
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*
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* @param byte The byte to send
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*/
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static __attribute__((always_inline)) inline void USBCDC_SendByte(uint8_t byte)
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{
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CDC_Device_SendByte(&VirtualSerial_CDC_Interface, byte);
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}
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/** Sends a block of data over the USB CDC serial port
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*
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* @param data The data to send
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* @param len The number of bytes
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* @return True on success, false on failure
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*/
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static __attribute__((always_inline)) inline bool USBCDC_SendData(uint8_t const *data, uint16_t len)
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{
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return CDC_Device_SendData(&VirtualSerial_CDC_Interface, (char const *)data, len) == ENDPOINT_RWSTREAM_NoError;
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}
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/** Attempts to read a byte from the USB CDC serial port
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*
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* @return The byte read, or -1 if there are no bytes available
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*/
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static __attribute__((always_inline)) inline int16_t USBCDC_ReadByte(void)
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{
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return CDC_Device_ReceiveByte(&VirtualSerial_CDC_Interface);
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}
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/** Forces any transmitted data to be sent over USB immediately
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*
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*/
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static __attribute__((always_inline)) inline void USBCDC_Flush(void)
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{
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CDC_Device_Flush(&VirtualSerial_CDC_Interface);
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}
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#endif /* HAL_AT90USB646_USBCDC_HW_H_ */
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