Why is this code not being able to change the default SPI value of 0 to 1, and also the bit shift on timer is not working

[AHald]

#define SPI2_CR2 *(__IO uint32 *)0x40003800

#define timer4_CR2 *(__IO uint32 *)0x40000800

void setup() 

{

 Serial.begin(115200);

}

void loop() 

{

 Serial.println("SPI");

 Serial.println(SPI2_CR2,BIN);

 SPI2_CR2=SPI2_CR2|(1<<0);

 Serial.println(SPI2_CR2,BIN);

 Serial.println("Timer");

 Serial.println(timer4_CR2,BIN);

 timer4_CR2 = timer4_CR2 | (1<<1);

 Serial.println(timer4_CR2,BIN);

 delay(1000);

}

I assumed that all registers initially has 0 as its value, so I tried to get the default ,i.e, 0 first from the Serial Monitor, then update that to 1, then get the updated value as 1 on the Serial Monitor. Same for the timer4, I first wanted to display the default value for the timer 4, then left-shift 1 bit, then display that. Can anyone please give me the rectified code? Just one constraint, not using any library functions.

[waclawek.jan]

CR2 offset in SPI is 0x04, so what you change is CR1. You change CPHA as that's the 0th bit. I don't exactly know what do you mean by "default SPI value", but if you mean the value of SPI_CR1.CPHA and it's not changing, then it's maybe because you did not enable the SPI clock in RCC.

JW

[AHald]

I assumed that all registers initially has 0 as its value, so I tried to get the default ,i.e, 0 first from the Serial Monitor, then update that to 1, then get the updated value as 1 on the Serial Monitor. Same for the timer4, I first wanted to display the default value for the timer 4, then left-shift 1 bit, then display that. Can anyone please give me the rectified code? Just one constraint, not using any library functions.

[waclawek.jan]

Do you have the SPI and TIM clocks enabled in RCC?

JW