Status Register

0x40000000

BIT 7

        BUSY
        1
      

BIT 6

        READY
        0
      

BIT 5

        ERROR
        1
      

BIT 4

        IRQ
        0
      

BIT 3..0

        RESERVED
        0000
      

Software Context

C++ Compiler

Attempted Write

      *status_reg = 0x01;
    

const qualifier

NO WRITE

Hardware Context

External Signals

Pin Voltage State

Pin 7: HIGH (3.3V)

volatile qualifier

    const uint8_t* const reg;
  

Read-only software pointer

    volatile uint8_t* reg;
  

Hardware-modified memory location

✓ Read Access Permitted

    uint8_t val = *reg;
  

⚡ Direct Hardware Update

Modifies register state directly, bypassing CPU optimization