Peter Stuge wrote: > I suggest: > > 1. Move forward with SAMD11 replacing FTDI > 2. Add CTS+RTS to the UART interface
I discovered that CTS+RTS are actually already connected to the USER FTDI in the rev03 schematic, but not to the MGMT FTDI. So at least some of the routing already exists! Paul, do you know if the STM32 USER UART init code enables nCTS+nRTS use? In a couple of days I'll check if wiring them to my SAMD11 daughterboard2 does anything. > 3. If time and space on the board allows it, also connect SPI > > Who does the hardware design changes? To support that effort I can > contribute the required connections on the SAMD11 side. SO14 has too few pins for both UART and SPI so it's either SO20 or QFN24. Since the SO20 package is fairly large I guess it will be QFN24. I/O SO20 QFN24 Signal PA04 20 3 SAMD11 UART TXD, to STM32 RX PA05 1 4 SAMD11 UART RXD, to STM32 TX PA08 4 7 SAMD11 UART RTS, to STM32 nCTS PA09 5 8 SAMD11 UART CTS, to STM32 nRTS PA15 7 12 SAMD11 SPI nCS, to STM32 NSS PA16 8 13 SAMD11 SPI DO/MOSI, to STM32 MOSI PA22 9 15 SAMD11 SPI SCK, to STM32 SCK PA23 10 16 SAMD11 SPI DI/MISO, to STM32 MISO PA28 11 18 SAMD11 nRESET * add 10k pull-up to 3V3 and 100nF to GND PA30 12 19 SAMD11 SWCLK * add 1k pull-up to 3V3 PA31 13 20 SAMD11 SWDIO PA24 14 21 SAMD11 USB D- PA25 15 22 SAMD11 USB D+ GND 16 23 3V3 17 24 * add 100nF Only nRESET, SWCLK and 3V3 need passives, all other signals can and should be directly connected. For SAMD11 programming and debugging the nRESET, SWCLK, SWDIO, GND and 3V3 signals need to be made available on a header. Please reuse the pinout from the SWD header for the STM32, ie. J1 in the rev03 schematic. The same programmer/debugger hardware can be used for both STM32 and SAMD11. //Peter _______________________________________________ Tech mailing list Tech@cryptech.is https://lists.cryptech.is/listinfo/tech
