C ------ EXCHSEQ.F77 ------------------------------------- 10.01.90 ---
C                                                        (c) M.Pester
C -------------------------------------------------------- 03.04.91 ---
C --- EXCHNG: Exchange NW words with the neighbour at link L, where the
C             processor with 1-bit at position L starts with "send"
C
      SUBROUTINE EXCHNG(L,NW,VO,VI)
        INCLUDE 'include/trnet.inc'
      DIMENSION VI(*),VO(*)
      LOGICAL   Btest
      IF (NCUBE .GT. 0) THEN
        IF (BTEST(ICH,L-1)) THEN
          CALL Send_Chan_0(NW,VO,L)
          CALL Recv_Chan_0(NW,VI,L)
        ELSE
          CALL Recv_Chan_0(NW,VI,L)
          CALL Send_Chan_0(NW,VO,L)
        ENDIF
      ENDIF
      RETURN
      END