Added SerialUPDI related documentation

This commit is contained in:
Dawid Buchwald 2021-12-26 14:34:01 +01:00
parent 993b8d7792
commit c48c5135d8
1 changed files with 112 additions and 1 deletions

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@ -307,6 +307,13 @@ The MPLAB(R) PICkit 4, MPLAB(R) SNAP, and Curiosity Nano boards are
supported in UPDI mode. The Curiosity Nano board is dubbed ``PICkit on supported in UPDI mode. The Curiosity Nano board is dubbed ``PICkit on
Board'', thus the name @code{pkobn_updi}. Board'', thus the name @code{pkobn_updi}.
SerialUPDI programmer implementation is based on Microchip's
@emph{pymcuprog} (@url{https://github.com/microchip-pic-avr-tools/pymcuprog})
utility, but it also contains some performance improvements included in
Spence Kohde's @emph{DxCore} Arduino core (@url{https://github.com/SpenceKonde/DxCore}).
In a nutshell, this programmer consists of simple USB->UART adapter, diode
and couple of resistors. It uses serial connection to provide UPDI interface.
@xref{SerialUPDI programmer} for more details and known issues.
@menu @menu
* History:: * History::
@ -1773,6 +1780,7 @@ functionality does not make sense for these boot loaders.
@menu @menu
* Atmel STK600:: * Atmel STK600::
* Atmel DFU bootloader using FLIP version 1:: * Atmel DFU bootloader using FLIP version 1::
* SerialUPDI programmer::
@end menu @end menu
@c @c
@ -1874,7 +1882,7 @@ least 4.5 V in order to work. This can be done using
@c @c
@c Node @c Node
@c @c
@node Atmel DFU bootloader using FLIP version 1, , Atmel STK600, Programmer Specific Information @node Atmel DFU bootloader using FLIP version 1, SerialUPDI programmer , Atmel STK600, Programmer Specific Information
@section Atmel DFU bootloader using FLIP version 1 @section Atmel DFU bootloader using FLIP version 1
Bootloaders using the FLIP protocol version 1 experience some very Bootloaders using the FLIP protocol version 1 experience some very
@ -1899,6 +1907,109 @@ signature check to be overridden with the @option{-F} option.
A @emph{chip erase} might leave the EEPROM unerased, at least on some A @emph{chip erase} might leave the EEPROM unerased, at least on some
versions of the bootloader. versions of the bootloader.
@c
@c Node
@c
@node SerialUPDI programmer, , Atmel DFU bootloader using FLIP version 1, Programmer Specific Information
@section SerialUPDI programmer
SerialUPDI programmer can be used for programming UPDI-only devices
using very simple serial connection.
You can read more about the details here
@url{https://github.com/SpenceKonde/AVR-Guidance/blob/master/UPDI/jtag2updi.md}
SerialUPDI programmer has been tested using FT232RL USB->UART interface
with the following connection layout (copied from Spence Kohde's page linked
above):
@example
-------------------- To Target device
DTR| __________________
Rx |--------------,------------------| UPDI---\/\/---------->
Tx---/\/\/\---Tx |-------|<|---' .--------| Gnd 470 ohm
resistor Vcc|---------------------------------| Vcc
1k CTS| .` |__________________
Gnd|--------------------'
--------------------
@end example
There are several limitations in current SerialUPDI/AVRDUDE integration,
listed below.
At the end of each run there are fuse values being presented to the user.
For most of the UPDI-enabled devices these definitions (low fuse, high
fuse, extended fuse) have no meaning whatsoever, as they have been
simply replaced by array of fuses: fuse0..9. Therefore you can simply
ignore this particular line of AVRDUDE output.
In connection to the above, @emph{safemode} has no meaning in context
of UPDI devices and should be ignored.
Currently available devices support only UPDI NVM programming model 0
and 2, but there is also experimental implementation of model 3 - not
yet tested.
One of the core AVRDUDE features is verification of the connection by
reading device signature prior to any operation, but this operation
is not possible on UPDI locked devices. Therefore, to be able to
connect to such a device, you have to provide @option{-F} to override
this check.
Please note: using @option{-F} during write operation to locked device
will force chip erase. Use carefully.
Another issue you might notice is slow performance of EEPROM writing
using SerialUPDI for AVR Dx devices. This can be addressed by changing
@emph{avrdude.conf} section for this device - changing EEPROM page
size to 0x20 (instead of default 1), like so:
@example
#------------------------------------------------------------
# AVR128DB28
#------------------------------------------------------------
part parent ".avrdx"
id = "avr128db28";
desc = "AVR128DB28";
signature = 0x1E 0x97 0x0E;
memory "flash"
size = 0x20000;
offset = 0x800000;
page_size = 0x200;
readsize = 0x100;
;
memory "eeprom"
size = 0x200;
offset = 0x1400;
page_size = 0x1;
readsize = 0x100;
;
;
@end example
USERROW memory has not been defined for new devices except for
experimental addition for AVR128DB28. The point of USERROW is to
provide ability to write configuration details to already locked
device and currently SerialUPDI interface supports this feature,
but it hasn't been tested on wide variety of chips. Treat this as
something experimental at this point. Please note: on locked devices
it's not possible to read back USERROW contents when written, so
the automatic verification will most likely fail and to prevent
error messages, use @option{-V}.
Please note that SerialUPDI interface is pretty new and some
issues are to be expected. In case you run into them, please
make sure to run the intended command with debug output enabled
(@option{-v -v -v}) and provide this verbose output with your
bug report. You can also try to perform the same action using
@emph{pymcuprog} (@url{https://github.com/microchip-pic-avr-tools/pymcuprog})
utility with @option{-v debug} and provide its output too.
You will notice that both outputs are pretty similar, and this
was implemented like that on purpose - it was supposed to make
analysis of UPDI protocol quirks easier.
@c @c
@c Node @c Node
@c @c