EUDAST
encx24j600_write_reg(priv, EUDAST, EUDAST_TEST_VAL);
eudast = encx24j600_read_reg(priv, EUDAST);
if (encx24j600_read_reg(priv, EUDAST) != 0) {
encx24j600_write_reg(priv, EUDAST, ENC_SRAM_SIZE);