This is a questionable fix for the Kinetis K22F that samples
this pin on release from reset to enable its EzPort which
makes the flash unusable and disables the rest of the micro.
Although the devices are only documented to have 64K flash,
they have been obeserved to have a full 128K, although the undocumented
half may be untested and have problems.
1) This version uses a direction control level shifters. We need to control
the direction of the TMS/SWDIO pin.
2.1) Because we want to support a large voltage range for SRST we use an
external dual MOSFET for asserting and sensing the SRST line. We have
added the hardware version 3 to be handled the same way as version 0.
Meaning using separate pins for assertion and sensing of the SRST line.
2.2) The new SRST sense circuit is inverting, thus we have dedicated
code for hardware version 3 that inverts the SRST status pin on read.
I was stuck trying to debug the issue why my probe would not find any attached targets. This is because I was doing the pin mapping as per the comments, and not the actual code. There is a mismatch!
This PR updates the comment to reflect the values set in code. :)
This adds a new function to the internal target interface
to allow the target to get control before reset is complete
so that it can do any additional work. On this target there
is a proprietary internal bit that has to be reset in some
cases to allow the core to continue operating.
BMPM V2 uses a biasing resistor for the true switch mosfet circuit.
Because of that the weak pull-up/down of the stm32 is not asserting the
correct gate voltage for the mosfets to fully switch through. Because of
that we need to use open drain configulation of the GPIO instead.
- Remove connect_assert_srst global.
- Attach functions always release reset.
- Platforms provide a method to poll the reset pin.
- Reset on scan is all internal to command.c
- Reset is released on a failed scan. Fixes#111
