WSJT-X/lib/ft8/chkcrc13a.f90
2019-02-10 20:43:51 +00:00

25 lines
653 B
Fortran

subroutine chkcrc13a(decoded,nbadcrc)
use crc
integer*1 decoded(90)
integer*1, target:: i1Dec8BitBytes(12)
character*90 cbits
! Write decoded bits into cbits: 77-bit message plus 13-bit CRC
write(cbits,1000) decoded
1000 format(90i1)
read(cbits,1001) i1Dec8BitBytes
1001 format(12b8)
read(cbits,1002) ncrc13 !Received CRC13
1002 format(77x,b13)
i1Dec8BitBytes(10)=iand(i1Dec8BitBytes(10),transfer(128+64+32+16+8,0_1))
i1Dec8BitBytes(11:12)=0
icrc13=crc13(c_loc(i1Dec8BitBytes),12) !CRC13 computed from 77 msg bits
nbadcrc=1
if(ncrc13.eq.icrc13) nbadcrc=0
return
end subroutine chkcrc13a