DZ_CSR_RX_DONE
while (((csr = dzr->csr) & (DZ_CSR_RX_DONE | DZ_CSR_TX_READY)) != 0) {
if ((csr & DZ_CSR_RX_DONE) != 0)
while ((dzcn->csr & DZ_CSR_RX_DONE) == 0)
while ((dzr->csr & DZ_CSR_RX_DONE) == 0)
for(; (dz->csr & DZ_CSR_RX_DONE) == 0;);
for(; (dz->csr & DZ_CSR_RX_DONE) == 0;);