Stratix® 10 Hard Processor System Technical Reference Manual
7.3.3.3. FPGA-to-HPS CCU to Peripherals (Device Non-Bufferable)
If your logic issues a Device Non-Buffereable transaction, write responses and read data are obtained from the final destination. Reads are not prefetched and writes are not merged. All transactions are non-modifiable, which means each transaction does not split into multiple transactions or merged with other transactions. All transactions from the same ID remains ordered.
Reads
- Read data returned directly from peripheral. Cache is not looked up.
| ATTRIBUTE | VALUE | NOTE |
|---|---|---|
| ARDOMAIN[1:0] | ’b01 | Inner Sharable |
| ARBAR[1:0] | ‘b00 | Normal access, respecting barriers |
| ARSNOOP[3:0] | ‘b0000 | ReadOnce |
| ARCACHE[3:0] | ‘b0000 | Device Non-bufferable |
| ARPROT[2:0] | ‘b011 or ‘b010 | Privileged access. Non-Secure access. Data access (or could be ‘b010 for Unprivileged access) |
| ARLEN[7:0] | The burst length for: WRAP burst type must be 1, 2, 4, 8 or 16 transfers. INCR burst type is 1 to 256 transfers. |
|
| ARSIZE[2:0] | The number of bytes in a transfer must be equal to the data bus width (128 bits) | |
| ARBURST[1:0] | ‘b01 or ‘b10 | Must be INCR(‘b01) or WRAP(‘b10) |
| ARLOCK[1:0] | ‘b00 | Must be normal access |
| ARQOS | Quality of Service. QoS identifier sent for each transaction. Implemented only in AXI4. |
Writes
- Write data is stored directly to peripheral. Cache is not looked up.
| ATTRIBUTE | VALUE | NOTE |
|---|---|---|
| AWDOMAIN[1:0] | ’b01 | Inner Sharable |
| AWBAR[1:0] | ‘b00 | Normal access, respecting barriers |
| AWSNOOP[2:0] | ‘b000 | WriteUnique (could be ‘b001 for WriteLineUnique) |
| AWCACHE[3:0] | ‘b0000 | Device Non-Bufferable |
| AWPROT[2:0] | ‘b011 or ‘b010 | Privileged access. Non-Secure access. Data access (or could be ‘b010 for Unprivileged access) |
| AWLEN[7:0] | The burst length for: WRAP burst type must be 1, 2, 4, 8 or 16 transfers. INCR burst type is 1 to 256 transfers. |
|
| AWSIZE[2:0] | The number of bytes in a transfer must be equal to the data bus width (128 bits) | |
| AWBURST[1:0] | ‘b01 or ‘b10 | Must be INCR(‘b01) or WRAP(‘b10) |
| AWLOCK[1:0] | ‘b00 | Must be normal access |
| AWQOS | Quality of Service. QoS identifier sent for each transaction. Implemented only in AXI4. |