158,159c158,160
< if (data_rate != 1 && data_rate != 2)
< fatal("Got unexpected data rate %d, should be 1 or 2\n");
---
> // 4 for GDDR5
> if (data_rate != 1 && data_rate != 2 && data_rate != 4)
> fatal("Got unexpected data rate %d, should be 1 or 2 or 4\n");