Agilex™ 7 Hard Processor System Technical Reference Manual
6.1.2.2.2. F2H Firewall (F2H to DDR)
The F2H Routing Firewall verifies that every Fabric transaction sets AxUSER[7:0] to either 0x04 or 0xE0 so that soft logic is not able to spoof the master ID of any other requestor like a core, TSN, DMA, and so on, in an attempt to work around the masterID firewall or other security features.
The firewall checks the Secure bit of a transaction (AxPROT) against the Secure state of the slave. A transaction that passes the firewall proceeds normally to the Slave. A transaction that fails the Firewall receives an error response with random data. Transactions that fail the firewall must never be presented to the Slave interface.
The following registers are associated with the F2H Firewall.
| Base Address of Registers | Register | Description | 
|---|---|---|
| firewall_ddr_fpga2sdram_inst_0_scr (@ 0xF8020100) | enable | Enable | 
| Enable_set | Sets Master Region Enable field when written with 1 | |
| Enable_clear | Clears Master Region Enable field when written with 1 | |
| region<N>addr_base | Base definition for F2H Region N | |
| region<N addr_baseext | Base extended definition for F2H Region N | |
| region<N addr_limit | Limit definition for F2H Region N | |
| region<N addr_limitext | Limit extended definition for F2H Region N |