Hello everyone,

I have problem with disabling SWIM interface on STM8S207K6 pin PD.1.

In reference manual (RM0016.pdf, page 53) there is written:

SWIM modes

After a power-on reset, the SWIM is reset and enters OFF mode.

1. OFF: Default state after power-on reset. The SWIM pin cannot be used by the
application as an I/O.

2. I/O: This state is entered by software writing to the SWD bit in the Global configuration
register (CFG_GCR). In this state, the SWIM pin can be used by the application as a
standard I/O pin. In case of a reset, the SWIM goes back to OFF mode.

3. SWIM: This state is entered when a specific sequence is performed on the SWIM pin.
In this state, the SWIM pin is used by the host tool to control the STM8 with 3
commands (SRST System Reset, ROTF Read On The Fly, WOTF Write On The Fly).

At beggining of my application I try to disable SWIM this way:

CFG->GCR |= 0x01; // disable SWIM interface

Then I download my application to MCU by RLINK and STVD.

1) First surprise is, that debugging is working even if I have disabled the SWIM in my application.

2) If I disconnect my board with MCU from RLINK - so there can't be any influence from RLink to MCU and after reset,
I still can't use pin PD1 (Im using PD1 for direct LED toggling and writing to this pin has no effect)

3) Same behavior is in Release mode or if I use STVP (ST Visual Programmer) to program the MCU.

In another manual UM0470.pdf (STM8 SWIM communication protocol and debug module, page 6) there is written:

Operating modes

After a Power-On Reset (powering of the device) the SWIM module is reset and enters in its
OFF mode.

1. OFF: In this mode the SWIM pin must not be used as an I/O by the application. It is
waiting for the SWIM entry sequence or to be switched to I/O mode by the application
software.
2. I/O: This state is entered by the software application by setting the IOM bit in the core
configuration register (MCR). In this state, the user application can use the SWIM pin
as a standard I/O pin, the only drawback is that there is no way to debug the
functionality of this pin with the built-in debug capabilities.
In case of a reset, the SWIM goes back to OFF mode.
3. ACTIVE: This mode is entered when a specific sequence is detected on the SWIM pin
while in OFF state. In this state, the SWIM pin is used by the host tool to control the
STM8 with 3 commands. (SRST System Reset, ROTF Read On The Fly, WOTF Write
On The Fly).

But I can't find in any manual or datasheet (and even in the internet) any description where the MCR register or IOM bit is!!!

And another strange behavior: One time I have success with disabling SWIM (LED connected to PD1 was toggling) but I don't know how has this happen...

Please, do you have same troubles with using PD1 as standard GPIO and SWIM together?
What is proper procedure to disable SWIM and use PD1 as standard GPIO?

Thanks for any replies

Milan.