Пишу
__io union {
unsigned char LCDPORT;
struct {
u08 unused: 3,
RW: 1,
Clock: 1,
Data: 2;

};
} @ 0X1B; // адрес PORTA
Потом обращаюсь
LCDPORT|=2<<Data;
или
Data=3;
и выдает ошибку вполне понятную
Error[e24]: Segment ABSOLUTE (seg part no 6, symbol "_A_PORTA" in module "main", address [3b-3b]) overlaps segment ABSOLUTE (seg part no 10, symbol "_A_LCDPORT" in module "main", address [3b-3b])