bMask = 0x3FFFFFF
jAddrMask = 0xFC000000
specialMask = 0x1FFFFF
rnMask = 0x3E0 # 1st argument  ARM Rn
rmMask = 0x1F0000  # second argument  ARM Rm
rdMask = 0x1F  # destination   ARM Rd
imMask = 0x3FFC00 # ARM I Immediate
shmtMask = 0xFC00 # ARM ShAMT
addrMask = 0x1FF000 # ARM address for ld and st
addr2Mask = 0xFFFFE0 # addr for CB format
imsftMask = 0x600000 # shift for IM format
imdataMask = 0x1FFFE0 # data for IM type
