WSJT-X/lib/fsk4hf/chkcrc12.f90

28 lines
854 B
Fortran

subroutine chkcrc12(decoded,nbadcrc)
use crc
integer*1 decoded(84)
integer*1, target:: i1Dec8BitBytes(11)
! Check the CRC
! Collapse 84 decoded bits to 11 bytes. Bytes 1-9 are the message,
! byte 10 and first half of byte 11 is the crc
do ibyte=1,9
itmp=0
do ibit=1,8
itmp=ishft(itmp,1)+iand(1,decoded((ibyte-1)*8+ibit))
enddo
i1Dec8BitBytes(ibyte)=itmp
enddo
! Pack the crc into bytes 10 and 11 for crc12_check
i1Dec8BitBytes(10)=decoded(73)*8 + decoded(74)*4 + decoded(75)*2 + decoded(76)
i1Dec8BitBytes(11)=decoded(77)*128 + decoded(78)*64 + &
decoded(79)*32 + decoded(80)*16 + decoded(81)*8 + decoded(82)*4 + &
decoded(83)*2 + decoded(84)
nbadcrc=1
if( crc12_check(c_loc (i1Dec8BitBytes), 11) ) nbadcrc=0
return
end subroutine chkcrc12