0x20000000u

0x20000000u is an unsigned integer literal used in C and C++ written in hexadecimal form with the unsigned suffix. The value of this constant is 0x20000000, which equals 536,870,912 in decimal and represents 2^29. In binary, it corresponds to a single 1 bit at position 29 within a 32-bit word.

As a constant, 0x20000000u is commonly used as a bit mask or flag in low-level programming. It can be combined with other flags using bitwise OR and tested with bitwise AND to determine whether the particular bit is set. For example, in code you might check whether a status word contains this bit: if (flags & 0x20000000u) { /* bit 29 is set */ }. It can also participate in bitwise operations to toggle or clear that bit.

In most modern environments, unsigned int is 32 bits, so 0x20000000u fits comfortably within the type’s range, and the unsigned suffix ensures unsigned arithmetic and avoids sign-related surprises in expressions. On unusual or non-standard platforms with different integer widths, the exact type of the constant may vary, but the value remains 536,870,912, and the bit position semantics remain tied to 2^29.

Related constants represent adjacent bit positions, such as 0x10000000u (bit 28) and 0x40000000u (bit 30). The 0x20000000u literal is primarily used for explicit, portable bit-level control in software dealing with flags, registers, or protocol options.