AnsweredAssumed Answered

[stm32f405rgt6] can't program + connection lost now and then

Question asked by zhao.liang.002 on Mar 25, 2016
Latest reply on Mar 25, 2016 by Clive One
I am trying to set up a minimal circuit for stm32f405rgt6 with breadboard and a breakout board.

The problems I have are:
1. I can connect to stm32f405rgt6 via ST-LINK utility, and see the content are all 0xFFFFFFFF starts from 0x08000000. But the connection is very unstable. Sometimes, it could last for like 5 minutes, sometimes, connection lost in a few seconds.
2. While stm32f405rgt6 is connected, I tried to click on "program & verify". I could get 2 kinds of errors:
2.1     "Elf Loader could not be transfered to device".
2.2     "Programming error @ 0x08000000"

I am not sure if the unstability is introduced by the breadboard. Do I have to use a PCB?
Or the chip I bought is not good? I only have one stm32f405rgt6 at hand right now.

Here are the detailed connection:
VDD(19,32,48,64)          3.3v
VSS(18,63)               ground
VDDA,VBAT               3.3
VSSA                    ground
I have 10*100nf + 4.7uF between VDD and ground.
2*2.2uF between VCAP_1, VCAP_2 and ground.
BOOT0                    ground

NRST,SWCLK,SWDIO connected with CN2(SWD) of the STM32F4-DISCOVERY board.