FXP_CSR_SCB_COMMAND
if (CSR_READ_1(sc, FXP_CSR_SCB_COMMAND) == 0) {
while (CSR_READ_1(sc, FXP_CSR_SCB_COMMAND) && --i)
CSR_READ_1(sc, FXP_CSR_SCB_COMMAND),
CSR_WRITE_1(sc, FXP_CSR_SCB_COMMAND, FXP_CB_COMMAND_NOP);
CSR_WRITE_1(sc, FXP_CSR_SCB_COMMAND, cmd);