To achieve the expected transaction behavior all Optimized and Generic slave ports have parameters to override the original transaction settings for all the Allocate bits and the Bufferable bit. They can be used to set the properties for AXI Masters that have non-programmable ARCACHE and/or AWCACHE configurations that do not match the desired transaction properties.
Parameters such as C_Sx_AXI_[GEN_]FORCE_[READ|WRITE]_[ALLOCATE|BUFFER] set the corresponding
bit to 1, whereas parameters such as C_Sx_AXI_[GEN_]PROHIBIT_[READ|WRITE]_[ALLOCATE|BUFFER] clear the bit to
0.
The following tables show the relationship between the corresponding parameters
and the ARCACHE and AWCACHE bits respectively for an Optimized port. An identical
mapping applies to the Generic S_AXI_GEN ports. The
Modifiable bit is not applicable.
| Other Allocate | Read Allocate | Bufferable |
|---|---|---|
| C_Sx_AXI_FORCE_WRITE_ALLOCATE | C_Sx_AXI_FORCE_READ_ALLOCATE | C_Sx_AXI_FORCE_READ_BUFFER |
| C_Sx_AXI_PROHIBIT_WRITE_ALLOCATE | C_Sx_AXI_PROHIBIT_READ_ALLOCATE | C_Sx_AXI_PROHIBIT_READ_BUFFER |
| Write Allocate | Other Allocate | Bufferable |
|---|---|---|
| C_Sx_AXI_FORCE_WRITE_ALLOCATE | C_Sx_AXI_FORCE_READ_ALLOCATE | C_Sx_AXI_FORCE_WRITE_BUFFER |
| C_Sx_AXI_PROHIBIT_WRITE_ALLOCATE | C_Sx_AXI_PROHIBIT_READ_ALLOCATE | C_Sx_AXI_PROHIBIT_WRITE_BUFFER |