En_pg_Mode:
clr ErrFlag ;
mov count,#030h ;
setb RST ; force target into reset
lcall delay10mS ; wait 1 ms (arbitrary)

En_pg:
mov a, #0ACh ; send first byte of enable code
lcall SPI ;
mov a, #053h ; send second byte
lcall SPI ;
mov a, #0FFh ; send third byte as dummy
lcall SPI ;
mov a, #0FFh ; send fourth byte dummy for receiving 69h
lcall SPI ;
; cjne A,#069h,enable_error ; received byte is not valid
sjmp Ena_End ;success entering program mode

enable_error:
djnz count,En_pg ;try this 30 times
mov dptr,#Failed_str ;
lcall OutStr ;
setb ErrFlag ;

Ena_End:
ret ;