==== Arduino Due ====
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The Due is a larger form factor Arduino board containing a ATSAM3X8E ARM Cortex-M3 processor
running at 84MHz.

There are two USB connectors on this board. One is labelled the native port which is
a direct connection to the processor. This allows the MCU to become a USB device in
its own right. The other port called the programming port connects to a serial
bridge for updating the firmware and it also allows regular UART communication.

===Programming===

==SAM BA==
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SAM BA is the ROM based bootloader found on the processor and
is connected to via the programming port.

[[tools:bossa|BOSSA]]

==JTAG==
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JTAG utilises the miniature header and can be used with the [[tools:segger|JLink EDU Mini]].

With an adapter the [[interfaces:usbocdh|Olimex UCD USB H]] can also be utilised.

<code>
openocd -f "interface/ftdi/olimex-arm-usb-ocd-h.cfg" -c "adapter speed 4000" -c "transport select jtag" -f "target/at91sam3XXX.cfg"
Open On-Chip Debugger 0.12.0-rc2+dev-00012-g4e077fdda (2022-11-12-16:05)
Licensed under GNU GPL v2
For bug reports, read
        http://openocd.org/doc/doxygen/bugs.html
adapter speed: 4000 kHz

jtag
cortex_m reset_config sysresetreq

Info : Listening on port 6666 for tcl connections
Info : Listening on port 4444 for telnet connections
Info : clock speed 500 kHz
Info : JTAG tap: sam3.cpu tap/device found: 0x4ba00477 (mfg: 0x23b (ARM Ltd), part: 0xba00, ver: 0x4)
Info : [sam3.cpu] Cortex-M3 r2p0 processor detected
Info : [sam3.cpu] target has 6 breakpoints, 4 watchpoints
Info : starting gdb server for sam3.cpu on 3333
Info : Listening on port 3333 for gdb connections
</code>

<code>
gdb-multiarch
(gdb) set architecture armv7
(gdb) target extended-remote localhost:3333
(gdb) info registers
r0             0x1ff               511
r1             0x8000000           134217728
r2             0x1                 1
r3             0x20070e38          537333304
r4             0x3e8               1000
r5             0x2711              10001
r6             0x81d8c             531852
r7             0x93cdc71           154983537
r8             0x2007002c          537329708
r9             0xd844d7c0          -666576960
r10            0x2358288a          592980106
r11            0x314f2ac3          827271875
r12            0xa8                168
sp             0x20087fd8          0x20087fd8
lr             0x8090b             526603
pc             0x8090a             0x8090a
xPSR           0x81000000          -2130706432
msp            0x20087fd8          0x20087fd8
psp            0x4921e0e0          0x4921e0e0
primask        0x0                 0
basepri        0x0                 0
faultmask      0x0                 0
control        0x0                 0
</code>
===Resources==

[[https://playground.arduino.cc/Bootloader/DueBootloaderExplained/|Due bootloader]]

[[https://www.microchip.com/en-us/product/ATSAM3X8E|Microchip ATSAM3X8E]]