Am 11.06.20 um 21:14 schrieb Eric Rullens: > Is there anything connected (e.g. a USB connector for programming) to P3.0 > and P3.1?
Yes. CH340G used for programming via the bootloader (using stcgal), and to be used later to get the serial data. Worked for me on the STC89C52RC. The STC8A8K64S4A12 board only also has LEDs on them. > Both IAP15W4K58S4 and STC8A8K64S4A12 seem to be able to switch > these pins to some kind of USB mode for programming. For STC8A8K64S4A12 the > manual mentions P3.2 needs to be at low level at powerup for this to work. Yes, stcgal uses that: Start stcgal, power-cycle the µC, stcgal will do its stuff and in the end reset the µC, which then should be back to normal (and just in case that reset doesn't fully work: power-cycling the board didn't make a difference for me either). > > If not already done: maybe a very simple test like clearing P3.0 or P3.1 > using the normal P3 register or direct bit access can show if the GPIO > function does work as expected? I tried that one the STC8A8K64S4A12, via GPIO I can blink the LEDs attached to P3.0 and P3.1: http://www.colecovision.eu/mcs51/STC8A8K64S4A12%20Development%20Board%20LED.shtml Philipp _______________________________________________ Sdcc-user mailing list Sdcc-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/sdcc-user
