;mine might be
       JNB P2.0,nxtr1    ; 2 cycles
       XCH A,r0          ; 1 cycle
       DEC A             ; 1 cycle
       JNZ nxtr1         ; 2 cycles
       clr P2.0          ; 1 cycle
nxtr1: XCH A,r0          ; 1 cycle (total 8 cycles/channel)