Slave Address Translation Examples

Slave Address Translation Examples - 1.0 English

Versal ACAP DMA and Bridge Subsystem for PCI Express Product Guide (PG344)

Document ID

PG344

Release Date

2022-05-20

Version

1.0 English

Example 1: BAR Size of 64 KB, with 1 Window Size 4 KB

Window 0: 4 KB with address translation of 0xF for bits [15:12].

Selections in Vivado IP configuration in the AXI BARs tab are as follows:
- AXI BAR size 64K: 0xFFFF bits [15:0]
- Address translation for bits[63:16] can be set in GUI. In this example [63:16] = 0x0
- Set Aperture Base Address: 0x0000_0000_0000_0000
- Set Aperture High Address: 0x0000_0000_0000_FFFF
The BDF table programming:
- Program 1 entries for 1 window
- Window Size = AXI BAR size/8 = 64K / 8 = 0x1FFF = 8 KB (13 bits). Each window max size is 8 KB.
- In this example for window size of 4K, 0x1 is programmed at 0x2430 bits [25:0].
- Address translation for bits [15:13] are programmed at 0x2420 and 0x2424.
- In this example, address translation for bits [15:13] are set to 0x7.

Table 1. BDF Table Programming
Program Value	Registers
0x0000_E000	Address translation value Low
0x0	Address translation value High
0x0	PASID/ Reserved
0x0	[11:0]: Function Number
0xC0000001	[31:30] Read/Write Access permission [29] : R0 access Error [28:26] Protection ID [25:0] Window Size ([25:0]*4K = actual size of the window)
0x0	reserved

For this example Slave address 0x0000_0000_0000_0100 will be address translated to 0x0000_0000_0000_E100.

Example 2: BAR Size of 64 KB, with 1 Window 8 KB

Window 0: 8 KB with address translation of 0x6 ('b110) for bits [15:13].

Selections in Vivado IP configuration in the AXI BARs tab are as follows:
- AXI BAR size 64K: 0xFFFF bits [15:0]
- Address translation for bits [63:16] can be done in GUI. In this example [63:16] = 0x0
- Set Aperture Base Address: 0x0000_0000_0000_0000
- Set Aperture High Address: 0x0000_0000_0000_FFFF
The BDF table programming:
- Program 1 entries for 1 window.
- Window Size = AXI BAR size/8 = 64K / 8 = 0x1FFF = 8 KB (13 bits). Each window max size is 8 KB.
- In this example for window size of 8K, 0x2 is programmed at 0x2430 bits [25:0].
- Address translation for bits [15:13] are programmed at 0x2420 and 0x2424.
- In this example, address translation for bits [15:13] are set to 0x6 ('b110).

Table 2. BDF Table Programming
Offset	Program Value	Registers
0x2420	0x0000_C000	Address translation value Low
0x2424	0x0	Address translation value High
0x2428	0x0	PASID/ Reserved
0x242C	0x0	[11:0]: Function Number
0x2430	0xC0000002	[31:30] Read/Write Access permission [29] : R0 access Error [28:26] Protection ID [25:0] Window Size ([25:0]*4K = actual size of the window)
0x2434	0x0	reserved

For this example, the Slave address 0x0000_0000_0000_0100 will be address translated to 0x0000_0000_0000_C100.

Example 3: BAR Size of 32 GB, and 4 Windows of Various Sizes

Window 0: 4 KB with address translation of 0xAAAAA for bits [31:12].
Window 1: 4 GB with no address translation on window.
Window 2: 64 KB with address translation of 0xBBBB for bits [31:16].
Window 3: 1 GB with address translation of 11111 for bits [34:30].

Selections in Vivado IP configuration in the AXI BARs tab are as follows:
- AXI BAR size 32G: 0x7_FFFF_FFFF bits [34:0].
- Address translation for bits [63:35] can be programmed in GUI. In this example [63:36] = 0xAB.
- Set Aperture Base Address: 0x0000_0AB0_0000_0000.
- Set Aperture High Address: 0x0000_0AB7_FFFF_FFFF.
The BDF table programming:
- Window Size = AXI BAR size/8 = 32 GB / 8 = 0xFFFF_FFFF = 4 GB (32 bits). Each window max size is 4 GB.
- Program 4 entries for 4 windows:
  - BDF entry 0 table starts at 0x2420.
  - BDF entry 1 table starts at 0x2440.
  - BDF entry 2 table starts at 0x2460.
  - BDF entry 3 table starts at 0x2480.
- Window 0 size 4 KB.
  - Program 0x1 to 0x2430 bits [25:0].
  - Address translation for bits [34:32] are programmed at 0x2420 and 0x2424.
  - Program 0x0000_0000 to 0x2420.
  - Program 0x0000_0007 to 0x2424
- Window 1 size 4 GB.
  - Program 0x10_0000 to 0x2450 bits [25:0].
  - No address translation because all address bits will be used by the window.
  - Program 0x0000_0000 to 0x2440.
  - Program 0x0000_0000 to 0x2444
- Window 2 size 64 KB.
  - Program 0x10 to 0x2470 bits [25:0].
  - Address translation for bits [34:32] are programmed at 0x2460 and 0x2464.
  - Program 0x0000_0000 to 0x2460
  - Program 0x0000_00005 to 0x2464
- Window 3 size 1 GB.
  - Program 0x4_0000 to 0x2490 bits [25:0].
  - Address translation for bits [34:30] are programmed at 0x2480 and 0x2484.
  - Program 0x0000_0000 to 0x2480.
  - Program 0x0000_0003 to 0x2484

Table 3. BDF Table Programming Entry 0
Offset	Program Value	Registers
0x2420	0x0000_0000	Address translation value Low
0x2424	0x7	Address translation value High
0x2428	0x0	PASID/ Reserved
0x242C	0x0	[11:0]: Function Number
0x2430	0xC0000001	[31:30] Read/Write Access permission [29] : R0 access Error [28:26] Protection ID [25:0] Window Size ([25:0]*4K = actual size of the window)
0x2434	0x0	reserved

Table 4. BDF Table Programming Entry 1
Offset	Program Value	Registers
0x2440	0x0000	Address translation value Low
0x2444	0x0	Address translation value High
0x2448	0x0	PASID/ Reserved
0x244C	0x0	[11:0]: Function Number
0x2450	0xC010_0000	[31:30] Read/Write Access permission [29] : R0 access Error [28:26] Protection ID [25:0] Window Size ([25:0]*4K = actual size of the window)
0x2454	0x0	reserved

Table 5. BDF Table Programming Entry 2
Offset	Program Value	Registers
0x2460	0x_0000	Address translation value Low
0x2464	0x05	Address translation value High
0x2468	0x0	PASID/ Reserved
0x246C	0x0	[11:0]: Function Number
0x2470	0xC000_00010	[31:30] Read/Write Access permission [29] : R0 access Error [28:26] Protection ID [25:0] Window Size ([25:0]*4K = actual size of the window)
0x2474	0x0	reserved

Table 6. BDF Table Programming Entry 3
Offset	Program Value	Registers
0x2480	0x0000_0000	Address translation value Low
0x2484	0x3	Address translation value High
0x2488	0x0	PASID/ Reserved
0x248C	0x0	[11:0]: Function Number
0x2490	0xC004_0000	[31:30] Read/Write Access permission [29] : R0 access Error [28:26] Protection ID [25:0] Window Size ([25:0]*4K = actual size of the window)
0x2494	0x0	reserved

For this example

the Slave address 0x0000_0000_0000_0100 will be address translated to 0x0000_0AB7_0000_0100.

the Slave address 0x0000_0001_0000_0100 will be address translated to 0x0000_0AB0_0000_0100.

the Slave address 0x0000_0002_0000_0100 will be address translated to 0x0000_0AB5_0000_0100.

the Slave address 0x0000_0003_0000_0100 will be address translated to 0x0000_0AB3_0000_0100.

The slave bridge does not support narrow burst AXI transfers. To avoid narrow burst transfers, connect the AXI smart-connect module which will convert narrow burst to full burst AXI transfers.