Stm8 bootloader communication problem

[yomer90]

In my application I try to access boot loader using USART1 and sending data through TI microcontroller
I set the baud rate to (4800 , 9600, 19200 , 38400 & 57600) and I tried with even and no parity
when I send SYNCHAR (0x7f)
I recieve ( 0xFF or 0x7f 0r 0x02)
what should I do ro recieve ACK message

 

[Easyrider83]

0xFF means that line is low during initialization. Use pull-up resistor to RX pin.

 

[yomer90]

I am using the internal pull up resistor with RX pin for UART1
when I try with UART3 it reply by ACK to the synchar only then when I send GET command I give me a wrong reply