Hello Chris,

I am posting the source of that section. (With another additional sfr this winbond microcontroller has, that doesn't work either)

sfr at 0xCF CHPCON;
...
CHPCON=0xFF;
aux=CHPCON;
printHex(aux);

ASM RESULT:

_CHPCON = 0x00cf
...
; as_usb.c:54: CHPCON=0xFF;
; genAssign
mov _CHPCON,#0xFF
; as_usb.c:55: aux=CHPCON;
; genAssign
mov r2,_CHPCON
; as_usb.c:57: printHex(aux);
; genCall
mov dpl,r2
push ar2
lcall _printHex

LCD RESULT
(printHex writes an hexidecimal number to the lcd):

CF

Thank you,

Xavier