Exclude segment from an address space.
Syntax
exclude_bd_addr_seg [‑target_address_space <arg>] [‑quiet] [‑verbose]
[<segment_to_exclude>]Returns
The newly excluded segment object, "" if failed.
Usage
| Name | Description |
|---|---|
[-target_address_space]
|
Target address space to exclude the slave segment from |
[-quiet]
|
Ignore command errors |
[-verbose]
|
Suspend message limits during command execution |
[<segment_to_exclude>]
|
segment to exclude |
Categories
Description
Exclude the specified AXI peripheral address segment from access by the AXI master it is mapped to, in order to support sparse connectivity and eliminate unneeded device resources.
This command lets you exclude specific peripherals from being accessed by specific AXI masters. For example, in the case where AXI peripherals P0 and P1 are connected to two masters M0 and M1, you can use sparse connectivity to let M0 access both P0 and P1, and let M1 accesses P1, but exclude it from P0.
- Unmapped - An AXI peripheral, or slave interface, is connected to an AXI master, but the peripheral has not been assigned an address segment in the master's address space and is not visible to the master.
- Mapped - The AXI peripheral is mapped into the AXI master's address space, assigned an address segment or range, and is accessible through the master.
- Excluded - The AXI peripheral is mapped to the AXI master, and has been assigned an address, but is not accessible to the master. The address segment that the AXI slave occupies within the master address space is also considered filled.
The purpose of excluding the address segment is to restrict access to peripherals that are connected to multiple masters. The validate_bd_design command will return a critical warning if a peripheral interface is connected to a master, but not mapped to an address segment of that master. However, by excluding the peripheral after it is mapped, the resources required to connect and provide access between the AXI master and the peripheral (the muxes and decoding for example) can be eliminated to conserve resources on the implemented design.
exclude_bd_addr_seg <master_addr_seg>
exclude_bd_addr_seg -target_address_space <master_addr_space> <slave_addr_seg> In the second command syntax, when a slave segment is specified, the slave will first be assigned or mapped to the specified AXI master address space, and then it will be excluded from access by the master.
This command returns nothing if successful, or returns an error if it failed.
Arguments
-target_address_space <arg> - (Optional) The target address space to map the address segment into. This option provides the mapping assignment usually performed by the assign_bd_address command, to let you assign the address segment to an address space, and exclude the address segment in a single command.
-quiet - (Optional) Execute the command quietly, returning no messages from the command. The command also returns TCL_OK regardless of any errors encountered during execution.
-verbose - (Optional) Temporarily override any message limits and return all messages from this command.
set_msg_config command.<segment_to_exclude> - Specify a single address segment object, bd_addr_seg, to exclude from access by its assigned AXI master.
Example
assign_bd_address [get_bd_addr_segs {axi_gpio_1/S_AXI/Reg }]
exclude_bd_addr_seg [get_bd_addr_segs microblaze_1/Data/SEG_axi_gpio_1_Reg]