The SMMU uses a 15-bit stream ID to perform address translations. This information is part of a transaction and indicates which processor or DMA unit originated the request.
Stream ID bits [9:0] are the same as the system management ID (SMID) bits (see APU SMID Bits [3:0]). Stream bits [14:10] are assigned by the TBU that the transaction passes through. There are seven TBUs:
- TBU 0 appends
000_00b - TBU 1 appends
000_01b - Etc.
- TBU 6 appends
001_10b