ATS Capability Control Register @0x5c4

ATS Capability and Control Register

Table 1. ats_cap_control
Bits SW Name Description Reset
4:0 R ATS Invalidate Queue Depth [ATSINVQD] The number of Invalidate Requests that the Function can accept before putting backpressure on the upstream connection. If 0 0000b, the Function can accept 32 Invalidate Requests. 0x1
5 R ATS Page Aligned Req [ATSPGALNREQ] If Set, indicates the Untranslated Address is always aligned to a 4096 byte boundary. 0x1
6 R Global invalidate supported [ATSGIS] If Set, the Function supports InvalidationRequests that have the Global Invalidate bit Set. If Clear, the Function ignores the Global Invalidate bit in all Invalidate Requests. 0x1
15:7 R Reserved [R15] Reserved 0x0
20:16 R/W ATS Smallest Translation Unit [ATSSTU] This value indicates to the Function the minimum number of 4096-byte blocks that is indicated in a Translation Completions or Invalidate Requests. This is a power of 2 multiplier and the number of blocks is 2STU. A value of 0 0000b indicates one block and a value of 1 1111b indicates 2^31 blocks. 0x0
30:21 R Reserved [R30] Reserved 0x0
31 R/W ATS Enable [ATSEN] When Set, the Function is enabled to cache translations. Default value is 0b. 0x0