For the Australian architectural firm, see ARM Architecture (Ashton Raggatt McDougall). For processor core designs, see List of ARM microarchitectures. ARM architectures The ARM logo Designer Arm Holdings Bits 32-bit, 64-bit Introduced 1985 ; 34 years ago ( 1985 ) Design RISC Type Register-Register Branching Condition code, compare and branch Open Proprietary 64/32-bit architectures Introduced 2011 ; 8 years ago ( 2011 ) Version ARMv8-A, ARMv8.1-A, ARMv8.2-A, ARMv8.3-A, ARMv8.4 Encoding AArch64/A64 and AArch32/A32 use 32-bit instructions, T32 (Thumb-2) uses mixed 16- and 32-bit instructions. ARMv7 user-space compatibility [1] Endianness Bi (little as default) Extensions SVE; All mandatory: Thumb-2, NEON, VFPv4-D16, VFPv4 Obsolete: Jazelle Registers General purpose 31× 64-bit integer registers [1] Floating point 32× 128-bit registers [1] for scalar 32- and 64-bit FP or SIMD FP or int...