HSRTRGR
if (sci_getreg(port, HSRTRGR)->size) {
sci_serial_out(port, HSRTRGR, rx_trig);
if (sci_getreg(port, HSRTRGR)->size)
return sci_serial_in(port, HSRTRGR) != 0;
[HSRTRGR] = { 0x54, 16 },