AnsweredAssumed Answered

STM32F401 - problems with SPI bootloader.

Question asked by anik.pasha on Sep 18, 2014
Latest reply on Dec 12, 2016 by Frick.Christian
Please, help me! 
I want to use SPI-bootloader in STM32F401 to update firmware in this controller.
But controller returns wrong answers.
For my experiments I use demoboard NUCLEO F401RE and application note AN4286 and AN2606.
I use SPI2 with configuration:
Slave mode, Full Duplex, 8-bit MSB, speed 1MHz, Polarity: CPOL Low, CPHA Low, NSS=0. Boot0=1, boot1=0.
After reset I send synchronization Byte 0x5A, but controller doesn't return 0xA5, it return  0x08 to me. I send 0x5A three times and then controller return 0xA5.
After that I send 0x00 and wait for ACK(0x79) or NACK(0x1F), but I have 0x83. Than I send 0x83 to controller many times and after that controller return 0x79.
Is it right?
After synchronization I try to send command (0x5A+0x00+0xFF) and I wait for ACK or NACK, but controller return 0x3C.

Help me, please!

P.S. I try to use UART1 bootloader - it works fine!