SPXg_REG1
#define spxg_switch_page(nr) (SPXg_REG1(0x20) = ((1 << (nr) & 0xff)) << 16)
while ((counter) && ((SPXg_REG1(0x0) & 0x8000) == 0))
while ((counter) && ((SPXg_REG1(0x0) & 0x8000) == 0))
while ((counter) && ((SPXg_REG1(0x0) & 0x8000) == 0))