Hi Magnus,

ES is associated with 0023h (like on every 8051).

SPIF is not bitaddressable.

There is an easy rule on the 8051:
Any SFR with the address 0*0h or 0*8h are bit addressable (* = 8 ... F). All others not.

So you can move it to a bitadressable register to test it.
in C:
while( (SPSR & SPIF_) == 0);

in assembler:
?C0006:
MOV A,SPSR
JNB ACC.7,?C0006


Peter