Minimum circuit for bare STM32 F2 lqfp64?

[skeezix]

Posted on January 10, 2014 at 23:38

I don't have one of the discovery boards (I know, I know ;), just a small stack of F205 chips.

I'm breadboarding one up so I can get a handle around it, and having trouble identifying the minimum circuit needed for it to run and program via ST LInk v2. (ie: Analogy to an avr .. with an avr, you just need a cap on each side, and the 4 power points, and the ISP pins and your'e good to go.) With the st-link v2, theres the jtag 20pin cable; in the data sheet for that, theres a half dozen lines of interest.. a bunch of GND's, and 4 or 5 lines for jtag signal (TDI, TDO, etc.) For the basic 64pin F2 chip, the datasheet notes I think.. 4 Vdd's, and 2 GNDs. (There was 2 that looked optional, I will check those.)  So I've got the 6 power points on the chip, pluis 4 JTAG lines from the cable into the chip, plus the cable has an assortment of GND and Vdd. Is that sufficient? I shoudln't need a crystal or oscilator, or anythign else to get up and going? I'll check, probably need some caps on the power lines to keep it stable. Pull up or reset, will check. Anything else? Shoudl it be only a half dozen pins to bring the chip alive and do basic read-flasg from st-link tool? Or is there more? Any 'minimim circuit' schematics? blinking led only schematics? Most google hits turn up the discovery boards or complex circuits; I want the absolute minimum circuit for the chip to be alive, and then will build up from there.. Any help is very much appreciated :) jeff

[Tesla DeLorean]

Posted on January 11, 2014 at 00:54

Analogue supplies, required, drive internal power-on-reset

VCAP1/2 pins require 2.2uF each for 1.2V regulator Wire up USART1 (PA9/10) or USART3 as option for System Loader BOOT0 pull down

[Tesla DeLorean]

Posted on January 11, 2014 at 01:29

GREEN JTAG, skip PB4 and PA15 if just SWD

PURPLE BOOT0 pull to ground, option to set high YELLOW USART1 optional BLUE VCAP each to 2u2F BLACK Ground RED 3.0 or 3.3V I'd add some decoupling and bulk caps to ground

[skeezix]

Posted on January 11, 2014 at 01:57

Oh, I forgot to note .. the rest of my board is at 5V so I'm figuring to run the STM32 at 3V or 3.3V (currently 3.0V).

- I'll look at the analog VCC's, thanks. - I'll check the voltage regulator part of the datasheet .. totally new to STM32 so had hoped to ignore that and 'supply the right voltage' to start with :) - seems like not many GND's, but a lot of VDD's and analogs.. cap from all the VDD's to GND to help stabalize? What was that about Boot0 System Loader option? USART1? .. as to SWD vs JTAG .. I was figuring full JTAG for now; I'm not really clear what SWD is yet; need to look it up. (Spoilt by how easy/trivial avr's and PICs are :) Thanks muchly clive .. babies screaming now, but I hope to get some bench time in an hour or two .. hopefully just a few more pins and it'll come alive! First yproject test, get a GPIO togglign up and down, so I can hit it with the o-scope and see that things are doing something. jeff

[skeezix]

Posted on January 11, 2014 at 03:42

Success.. just adding the analog VDD/GND brought it to life, so STLink32 utility could read memory and flash it. I'll add the other bits as well to be safe.

Thanks for the tips and the picture.. I'll save that image to my datasheet collection. jeff