-------------------------------------------------------------------------------
SWD
-------------------------------------------------------------------------------

This is a set of example captures of the ARM SWD (version 1) protocol.

Details:
http://infocenter.arm.com/help/index.jsp?topic=/com.arm.doc.ihi0031c/index.html
(registration required)


Logic analyzer setup
--------------------

  Probe       SWD
  ---------------
  0           swclk
  1           swdio


Data
----

Different SWD sessions showing different types of behaviour:

* stlink_openocd/

Using an STLINK-V2 adapter via OpenOCD 0.9.0 development
version. Device under test is a Nordic nRF51822.

Command line:

  $ openocd -f interface/stlink-v2.cfg -c 'transport select hla_swd' \
            -f target/nrf51.cfg

** stlink_openocd/init.sr
   Intiliasing device, IDCODE read, etc.
   OpenOCD args: -c "init; exit"

** stlink_openocd/init_write_0xabbabeeb.sr
   Initialise, write 20 bytes of 0xabbabeeb at start of RAM.
   OpenOCD args: -c "init; halt; mww 0x20000000 0xabbabeeb 20; exit"

** stlink_openocd/wait_retry.sr
   Capture showing an SWD WAIT with overrun mode not enabled (in contrast to
   ftdi_openocd/wait_retry.sr), adapter immediately retries and gets an OK
   response.

   For this capture OpenOCD was patched with this change (known to induce
   SWD WAITs): http://openocd.zylin.com/#/c/2204/

   OpenOCD args: -c "init; reset halt; flash fillw 0 0xabbabeeb 2048; exit"