when i connect to program with a usb st-link block i connect two pins swclk & swdio & gnd of coursePB3 and PB4 pins are reserved for the debug interface which is enabled when you upload with STlink.
so as usual, i start up cubemx and played with the sys debug item again, looking at a 103c8
using 2 wire serial, the pins pa13 & pa14 are setup, their naming suggests sys_jtck_swclk & sys_jtms_swdio.
4 wire jtag in addition to above uses pa15 & pb3
5 wire jtag adds on pb4
so the query is why are we setting a jtag mode for st-link ?
why wouldn't we want to just use the minimum pin count we can get away with ?
is there anything extra we can get specifying a jtag mode ?
not with a usb block using 3 wires as i understand it.
my st-link is one of these blue/white egg shaped things:
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0483:3748 STMicroelectronics ST-LINK/V2
no doubt there'll be a dearth for winxx
<edit>oops i seem to have inverted the meaning of dearth </edit>