Swim - Chip does not answer

johanbleumers9 · ‎2012-09-06

Posted on September 06, 2012 at 09:37

Hi,

I am debugging software for an STM8S105x6, using the programmer from the STM8S-Discovery board and STVD software.

All went fine, until suddenly an error popped up while entering debug mode: '** Connection error (usb://usb): swim error [30006]: comm init error: chip does not answer'. Also STVP cannot connect to the MCU.

I've tried to other boards (that have worked before). I've directly soldered the SWIM wires to the board. Without any result.

When i changed the programmer a first time, the problem remained. But with a third programmer, the problem was solved.

But after a while the problem came back.

This programmer still seems to be ok, because i can program the MCU on the demoboard itself.

I have no clue what can be the problem.

Some more info about the board:

* GND, reset and dataline for SWIM are connected. VCC is not connected

* The reset pin has a 10nF cap to gnd and 10K to the VCC (i have tried to remove both)

* VCC = 5V1

Anyone an idea what is wrong???

Regards,

Johan

kirill · ‎2014-08-01

Posted on August 01, 2014 at 17:05

The SWIM pin must be pulled up to Vcc with 470-680 Ohm resistor. When I tried to use 1k resistor, I was getting problems similar to yours.

jherrmann · ‎2015-11-16

Posted on November 16, 2015 at 19:27

I was getting the same connection error intermittently on my STM8L152 design. I had the SWIM circuitry wired exactly as the demo board, Pin 1 to my on board regulator, Pin 2 to PA0, Pin 3 to GND, and Pin 4 to PA1. Then I was reading through the ''STM8 SWIM communication protocol and debug module'' (UM0470) manual and on page 6 it says that the SWIM module will either use the LSI or HSI, not external clocks or crystals. In the rest of the manual it only refers to using the HSI. So I switched from my LSE crystal to the HSI clock, and haven't gotten that connection error.