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This version (22 Nov 2019 16:40) was approved by sergiu arpadi.
This version (22 Nov 2019 16:40) was approved by sergiu arpadi.This is an old revision of the document!
Table of Contents
System ID
The System ID solution is comprised of 2 cores: the axi_sysid which provides the AXI Lite interface and sysid_rom which acts as a ROM and contains the data. Together they provide the user with information regarding the conditions in which the hardware system was built.
Block Diagram
Introduction
The System ID information is used to provide information about the system’s bit file to facilitate future debugging actions. This information will be stored internally in a ROM and will be made available to the system via the AXI Lite interface.
AXI Sysid IP Configuration Parameter
| Name | Description | Default Value |
|---|---|---|
ROM_WIDTH | ROM width | 32 |
ROM_ADDR_BITS | Number of address bits | 9 |
AXI Sysid IP Signal and Interface Pins
| Interface | Pin | Type | Description |
|---|---|---|---|
sys_rom_data | input | Data input from System ROM | |
pr_rom_data | input | Data input from PR ROM | |
rom_addr | output | ROM address output | |
s_axi | AXI Slave Memory Map interface | ||
s_axi_aclk | input | AXI clock | |
s_axi_aresetn | input | AXI reset | |
Sysid ROM IP Configuration Parameter
| Name | Description | Default Value |
|---|---|---|
ROM_WIDTH | ROM width | 32 |
ROM_ADDR_BITS | Number of address bits | 6 |
PATH_TO_FILE | Location of ROM init file | “path_to_mem_init_file” |
Sysid ROM IP Signal and Interface Pins
| Interface | Pin | Type | Description |
|---|---|---|---|
clk | input | Input clock | |
rom_addr | input | Address input | |
rom_data | output | Data output |
Register Map
System ID (axi_system_id)
Clocking
The IP core runs on the AXI clock and requires a frequency of 100MHz.
Theory of Operation
The System ID consists of a system of 2 or more IP cores where one provides access to the AXI Lite interface, and the other behaves as a ROM. There can be more than one ROM IP cores if required. The information contained by the ROM will be generated and written at synthesis and will provide details as revealed further in this document.
Once written, these contents cannot be changed, only read. These ROMs will be 32 bits wide with a fixed length of 512 lines for the System ROM (2KiB). The secondary PR ROM will generally be smaller.
Data format
Common Header
| Field size | Field | Value | Data format |
|---|---|---|---|
| 4B * | Common Header Format Version | 31:16 - reserved, write as 0000h ; 15:0 - format version number | hex |
| 4B * | Internal Use Area Starting Offset | 00000000h indicates that this area is not present | hex |
| 4B * | Board Area Starting Offset | 00000000h indicates that this area is not present | hex |
| 4B * | Product Info Area Starting Offset | 00000000h indicates that this area is not present | hex |
| 4B * | System Custom String Area Starting Offset | 00000000h indicates that this area is not present | hex |
| 4B | PR custom string area (ROM2) | 00000000h indicates that this area is not present | hex |
| 9 x 4B | Padding | 00000000h | hex |
| 4B * | Checksum | hex |
Internal Use Area
| Field size | Field | Data format |
|---|---|---|
| 44B * | Git tag (sha) | hex |
| 4B * | Git clean check | hex |
| 4B * | Vadj check | hex |
| 12B * | Build date/time as seconds since 1970-01-01_00:00:00 (UTC) | hex |
| 4B * | Padding (00000000h) | hex |
| 4B * | Checksum | hex |
* = These fields are MANDATORY
Common Header: The Common Header is mandatory for all System ID Information Device implementations. It holds version information for the overall information format specification and offsets to the other information areas. The other areas may or may not be present based on the application of the device. A field is specified as ‘Null’ or ‘not present’ when the Common Header has a value of 00h for the starting offset for that area.
Common Header Format Version: This area version information regarding the Common Header.
Internal Use Area: This area contains information describing the circumstances in which the project was built.
Product Info Area: Contains the name of the targeted product. Data converted from ASCII to hex. Size: Variable, 32 Bytes default.
System Custom String: Character string written by the user. Data converted from ASCII to hex. Size: Variable, 32 Bytes default.
Board Info Area: This area provides the name of the platform that the project is targeting. Data converted from ASCII to hex. Size: 32 Bytes. System Custom String Area This area provides a region where a custom string supplied by the user will be written to. This will be stored in ROM1, inside the system bit. Data converted from ASCII to hex. Size: Variable, 32 Bytes default.
PR Custom String Area: This area provides a region where a custom string provided by the user will be written to. This will be stored in ROM2, inside the PR bit where available. Data converted from ASCII to hex.
Working with the Core
The System ID solution is automatically placed into a project by the Tcl code ADI uses to build projects. It is instantiated in two stages, first in the “Common” bd.tcl of each of the supported FPGA boards and second in the system_bd.tcl of each project.
The information written to the System ID ROM(s) is obtained from Vivado in the early stages of project building. It is at this point that the user can choose the information that will be written to the “Custom String” areas.
set sys_cstring "sys rom custom string placeholder" sysid_gen_sys_init_file $sys_cstring
resources/fpga/docs/axi_sysid.1573730445.txt.gz · Last modified: 14 Nov 2019 12:20 by sergiu arpadi