The top level module of the Holoscan Sensor Bridge IP is “HOLOLINK_top”.
The Holoscan Sensor Bridge IP is designed to be easily configurable to various use case of the IP, such as number of sensors and Ethernet ports. It’s also designed to be compatible with multiple FPGA vendors. The following describes the configurations available to user.
Macro Definitions
The Holoscan Sensor Bridge definitions file, “HOLOLINK_def.svh”, defines the following macros.
The macros can be configured to user’s application of the Holoscan Sensor Bridge IP. The default macro value is the configuration that has been tested and verified.
Table 13
**Macro | Tested Values | Description |
|---|---|---|
| FPGA_VENDOR | LATTICE, PSG, MICROCHIP | Defines the FPGA Vendor used. |
| HIF_CLK_FREQ | 156250000 (for DATAPATH_WIDTH=64) 201416016 (for DATAPATH_WIDTH=512) | Clock frequency of the Host Interface. Unit is in Hz |
| APB_CLK_FREQ | 19531250 (for DATAPATH_WIDTH=64) 100000000 (for DATAPATH_WIDTH=512) | Clock frequency of the APB Interface. Unit is in Hz |
| BOARD_ID[7:0] | Any value | Used in Enumeration packet |
| ENUM_EEPROM | Defined or undefined | When defined, read the contents of the Enumeration packet from from external non-volatile memory. If undefined, use the macro definitions. |
| MAC_ADDR[47:0] | Any value | Used in Enumeration packet if ENUM_EEPROM is undefined. |
| BOARD_VER[159:0] | Any value | Used in Enumeration packet if ENUM_EEPROM is undefined. |
| BOARD_SN[55:0] | Any value | Used in Enumeration packet if ENUM_EEPROM is undefined. |
| FPGA_CRC[15:0] | Any value | Used in Enumeration packet if ENUM_EEPROM is undefined. |
| MISC[31:0] | Any value | Used in Enumeration packet if ENUM_EEPROM is undefined. |
| DATAPATH_WIDTH | 64, 512 | Width of the AXI Stream TDATA in bits. This number must be byte-aligned. Meanind, it must be a number divisible by 8. |
| DATAKEEP_WIDTH | DATAPATH_WIDTH/8 | Width of the AXI Stream TKEEP.This should not be changed. |
| DATAUSER_WIDTH | 1 | Width of the AXI Stream TUSER signal. |
| SENSOR_IF_INST | 1-2 | Number of Sensor interfaces. |
| HOST_IF_INST | 1-2 | Number of Host interfaces. |
| SPI_INST | 1-8 | Number of SPI interfaces. |
| I2C_INST | 1-8 | Number of I2C interfaces. |
| GPIO_OUT | 0-255 | Number of GPIO Output bits. |
| GPIO_IN | 0-255 | Number of GPIO Input bits. |
| REG_INST | 1-8 | Number of user register. |
| SIF_SORT_RESOLUTION | DO NOT TOUCH | TBD. Do not change. |
| SIF_VP_COUNT | DO NOT TOUCH | TBD. Do not change. |
| SIF_VP_SIZE | DO NOT TOUCH | TBD. Do not change. |
| SIF_NUM_CYCLES | DO NOT TOUCH | TBD. Do not change. |
| SIF_DYN_VP | DO NOT TOUCH | TBD. Do not change. |
| SIF_MIXED_VP_SIZE | DO NOT TOUCH | TBD. Do not change. |
| N_INIT_REG | Integer value | Number of initialization registers. |
Enumeration Packet
The Holoscan Sensor Bridge IP transmits a broadcast UDP enumeration packet approximately once per second. The content of the enumeration packet can be sourced from on-board, non-volatile memory or from macros defined in the “HOLOLINK_def.svh”. Each of the macros used for enumeration packet is further explained below.
BOARD_ID: This macro defines the Board ID. This macro must be defined and is not optionally stored in the non-volatile memory.
ENUM_EEPROM: When this macro is defined, the contents of the below macros are retrieved from an on-board, non-volatile memory upon boot-up. The contents of the below macros must be stored in specific address of the non-volatile memory. Further details can be provided upon request.
MAC_ADDR: This macro defines the UDP MAC Address of the FPGA. The MAC Address is incremented by 1 for each Host interface available. For example, if the MAC_ADDR macro is defined as 48’hCAFEC0FFEE00, Host Interface 0 will have address 48’hCAFEC0FFEE00 and Host Interface 1 will have address 48’hCAFEC0FFEE01, and so on.
This macro is used only if ENUM_EEPROM macro is undefined.
BOARD_VER: This macro defines the Board Version and is used only if ENUM_EEPROM macro is undefined.
BOARD_SN: This macro defines the Board Serial Number and is used only if ENUM_EEPROM macro is undefined.
FPGA_CRC: This macro defines the CRC of the FPGA bit image and is used only if ENUM_EEPROM macro is undefined. The intended function is for software to check the validity of the FPGA bit image by checking it against what the software calculates. This function is not yet supported.
MISC: This macro defines miscellaneous information and is used only if ENUM_EEPROM macro is undefined.
The Holoscan Sensor Bridge IP provides system initialization function to write to registers upon power up. This function is used to initialize the Ethernet block to establish ethernet connection between the FPGA and the host, and can be used for any other user function in the top level design.
The list of registers to be initialized is defined in “Hololink_def.svh” as “init_reg” array. The “init_reg” is an unpacked array, sized [N_INIT_REG] [63:0], where the N_INIT_REG macro defines the number of registers to be initialized and the 64-bit vector is used to define the 32- bit address of register at [63:32] and the 32-bit write data at [31:0].
To give an example of one of the init_reg array entry:
{32’h1000_0020, 32’h0000_00FF} //init_reg[0]
Will write to the User REG_INST_0 block address offset 0x0000_0020 the data 0x0000_00FF.
Once system initialization is complete, the “o_init_done” port will be asserted high in “i_apb_clk” domain. User can use this signal to gate their logic if it’s dependent on ethernet block initialization.