STM8S003F3 reset pin - output frequency

[Vindhyachal.takniki]

1. I have made a circuit using STM8S003F3.
I don't understand somehow when I probe reset pin of MCU, it is giving 12Khz freq output.
Thus I am unable to program/debug the MCU.

2. I have removed everything else from board. Just +5V supply & MCU.
MCU supply is decoupled by 0.1u & 1u caps.
Vcap pins is decoupled by 1uF cap.
Reset pin is decoupled by 0.1uF cap.
That's it . Nothing else on circuit.

3. I have probed VCC pin of MCU, I get clean +5V across it.
Probing Vcap pin gives +2V clean.
I have also removed 0.1u cap from reset pin & then checked the bare pin but same result.

Edit: I have also changed 2 MCU but same results

[Psi]

Looking at the datasheet the watchdog can be set between 64ms and 75us.

75us is ~12khz,  coincidence?  i doubt it 

Either your code, or the option bytes, are enabling one of the chips watchdogs and it's not being cleared. It will keep tripping every 75us (or whatever its set to) and pull RESET to ground, then repeat.

Quickest way to confirm is put some watchdog clear commands into main().

[Vindhyachal.takniki]

Problem is its fresh piece I have soldered.
Due to reset pin frequency, I can enter my code into it. Debugger replies that it cannot communicate.

[Vindhyachal.takniki]

Problem solved. By mistake I had connected 1pf at vcap pin instaed of 1uF.