2014-06-05 10:36 PM
Hello,
I am designing a board using STM32F030F4P6. I have to use STM32F0 Discovery board STLINK for ISP. Checking the schematics of Discovery board, I found out that the ISP connector (SWD) is connected as follows: 1.3.3V 2.SWCLK 3.GND 4.SWIO 5.NRST 6.PB3 of the STM32 controller on board. Now, I have trouble understanding the 6th connection. the signal name is given as T_SWO and it is connected to PB3. what is this signal? In TSSOP 20 package of STM32F030F4P6, this pin(PB3) is not there. so where should I connect 6th pin of ISP header? or can i leave it open? Referances: MB1034: Discovery board schema DM00088500.pdf: STM32F030F4P6 Datasheet DM00039193.pdf:STM32F051xx Datasheet #stm32f03x62014-06-06 04:50 AM
PB3 SWO is typically used in support of the SWV (Serial Wire Viewer), as far as I'm aware the Cortex-M0 does not support this functionality (Debug/Trace), or JTAG, so the pin can be left unconnected.
If may be connected in the schematic due to the way ST shares a common footprint over several processor families, allowing migration up and down the feature/power/cost line. I, personally, would opt to use the standard 10-pin 0.05'' pitch ARM programming header over the ST ISP one.