Arduino Uno, UART speed issue?

Question

Arduino

Hello!
Programming an arduino in C. I used initialization and forwarding according to the atmega328 manual. When viewing in the terminal on the settings specified in the code, incorrect data is displayed, but if you set not 9600, but 19200 in the terminal, then the characters are displayed normally. If you use the standard Arduino IDE examples, then everything works correctly.
Firmware

#include <avr/io.h>

#define FOSC 16000000 // Clock Speed
#define BAUD 9600
#define MYUBRR FOSC/16/BAUD-1

void USART_Init( unsigned int ubrr)
{
/*Set baud rate */
UBRR0H = (unsigned char)(ubrr>>8);
UBRR0L = (unsigned char)ubrr;
/*Enable receiver and transmitter */
UCSR0B = 1<<TXEN0;
/* Set frame format: 8data, 1stop bit */
UCSR0C = 3<<UCSZ00;
}

void USART_Transmit( unsigned char data )
{
/* Wait for empty transmit buffer */
while ( !( UCSR0A & (1<<UDRE0)) )
;
/* Put data into buffer, sends the data */
UDR0 = data;
}

void main( void )
{
USART_Init(MYUBRR);
  while(1){
    USART_Transmit('b');
  }
}

Makefile just in case

#Контроллер, установленный на плате. Может быть другим, например atmega328 
DEVICE     = atmega328p

#Тактовая частота 16 МГц 
CLOCK      = 16000000

#Команда запуска avrdude. Ее нужно скопировать из Arduino IDE.
AVRDUDE = C:\Users\User\Desktop\arduino-1.0.4\hardware/tools/avr/bin/avrdude -CC:\Users\User\Desktop\arduino-1.0.4\hardware/tools/avr/etc/avrdude.conf -v -v -v -v -patmega328p -carduino -P\\.\COM3 -b115200 -D

OBJECTS    = main.o

COMPILE = avr-gcc -Wall -Os -DF_CPU=$(CLOCK) -mmcu=$(DEVICE)

all:	main.hex

.c.o:
  $(COMPILE) -c $< -o [email protected]

.S.o:
  $(COMPILE) -x assembler-with-cpp -c $< -o [email protected]

.c.s:
  $(COMPILE) -S $< -o [email protected]

flash:	all
  $(AVRDUDE) -U flash:w:main.hex:i

clean:
  rm -f main.hex main.elf $(OBJECTS)

main.elf: $(OBJECTS)
  $(COMPILE) -o main.elf $(OBJECTS)

main.hex: main.elf
  rm -f main.hex
  avr-objcopy -j .text -j .data -O ihex main.elf main.hex
  avr-size --format=avr --mcu=$(DEVICE) main.elf

Answer 1

The problem turned out to be in the initial initialization, there is garbage in the memory of the UCSR0A-C registers, but I assumed that there were zeros.
Fixed the code and everything worked

#include <avr/io.h>

#define FOSC 16000000 // Clock Speed
#define BAUD 9600
#define MYUBRR FOSC/16/BAUD-1

void USART_Init( unsigned int ubrr)
{
/*Set baud rate */
UCSR0A = 0;
UCSR0B = 0;
UCSR0C = 0;
UBRR0H = (unsigned char)(ubrr>>8);
UBRR0L = (unsigned char)ubrr;
/*Enable receiver and transmitter */
UCSR0B = 1<<TXEN0;
/* Set frame format: 8data, 1stop bit */
UCSR0C = 3<<UCSZ00;
}

void USART_Transmit( char data )
{
/* Wait for empty transmit buffer */
while ( !( UCSR0A & (1<<UDRE0)) )
;
/* Put data into buffer, sends the data */
UDR0 = data;
}

void main( void )
{
USART_Init(MYUBRR);
  while(1){
    USART_Transmit('a');
  }
}

Answer 2

Are UBRR0H and others like them available for reading?