32-bit architecture

32- bit architecture, it is understood in the computer processor architecture, the word length is 32 bits.


  • MIPS ( SGI later ) the MIPS architecture (32- bit and 64- bit)
  • Sun Microsystems SPARC - series (32 -bit, 1995 64- bit UltraSPARC )
  • The Motorola 68000 family
  • Apple / IBM / Motorola PowerPC series (32- bit and 64- bit)
  • Built by Intel, AMD and other x86 processors family (32 -bit, since 2003, 64 -bit AMD64)
  • Digital or Compaq later the VAX architecture (32- bit)
  • ARM, the ARM architecture, licensed to numerous processor manufacturer
  • Atmel AVR32 architecture the
  • Of Infineon TriCore architecture
  • DLX microprocessor: hypothetical 32 -bit architecture

And various other designs.


In simplified terms means 32- bit processors that are designed by their ALU design so that 32 -bit ( ie 4 bytes) can be simultaneously processed or during a cycle. This includes the external and internal design of the data bus and the width of the register set with a. This applies analogously to the standard addressing modes, the bit width of the arithmetic unit ( ALU) in principle from that of the address unit can differ (such as even with 64 -bit CPUs).

32 bits are a 32 digits long number series of ones and zeros.


The advantages of höherbittigen architecture In computer architecture integer values ​​( by the wider ALU ), which, for example, benefits in encryption algorithms, graphical calculations (for example, fixed-point arithmetic for computer games), 32 -bit file systems or multimedia formats (MPEG -2, MP3) brings.


Without specially adapted operating systems, however, can be drawn is usually not a big advantage from the change from 16 -bit to 32 -bit CPUs.

Similar to SIMD or the AltiVec extensions so usually specially adapted software is necessary for 32- bit systems.

However, does not have any system with 32- bit wide data path also has a 32- bit wide address path, ie, a 4- GiB address space. For older IBM mainframes ( System/360 and System/370 ) only 24 bits are used for addressing (16 - MiB address space ). Since the excess bytes was used by the operating system and application programs for flag bits, the transition to 31- bit addressing ( 2 GiB address space ) with only one flag bit was complex. In some systems, the address path is narrower or larger than 32 bits. Since the Pentium Pro, for example, the x86 CPUs can address with 36-bit, which corresponds to an address space of 64 GiB.

Programming model

Under the C programming language itself suggests the number of bits in particular in the size of the data types void *, int, and sometimes even at long, and their unsigned counterparts down. With the proliferation of 32 -bit architectures have been given equal weight usually set the three types on the width of 32 bits, so that data of int type, long type and pointer - type are the same. This is called ILP32 abbreviated. For backward compatibility with the 16- bit architecture, which was mostly designed as IP16, it had partly also left the int type is 16 -bit, called LP32, or set the Long type to double the width of 64 -bit, called IP32. The first versions of DOS / Windows and Mac OS that worked with LP32 and 16-bit "int", during the early Ultrix versions with IP32 and 64-bit "long" worked. Derlei programming models, however, have not enforced - all current Unix-like 32 -bit operating systems, press the 32 -bit architecture in a ILP32 - type model.