> For clean Markdown of any page, append .md to the page URL.
> For a complete documentation index, see https://docs.nvidia.com/holoscan/sensor-bridge/llms.txt.
> For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://docs.nvidia.com/holoscan/sensor-bridge/_mcp/server.
The port descriptions for the Holoscan Sensor Bridge IP are described in the following
sections. For more information on macros defined in "HOLOLINK\_def.svh", refer to
[Macro Definitions](/holoscan/sensor-bridge/fpga-ip/ip-integration#macro-definitions)
## Global Reset
Table 1 Global Reset Port
| **Signal Name** | **Direction** | **Description** |
| --------------- | ------------- | --------------------------------------- |
| i\_sys\_rst | Input | Global, Asynchronous, Active High Reset |
## User Register Ports
Table 2 User Register Clock and Reset Ports
| **Signal Name** | **Direction** | **Description** |
| --------------- | ------------- | -------------------------------------- |
| i\_apb\_clk | Input | APB Clock. Must be greater than 20MHz. |
| o\_apb\_rst | Output | APB Synchronous, Active High Reset |
Table 3 User Register APB Ports
| **Signal Name** | **Direction** | **Description** |
| ------------------------------------------ | ------------- | ------------------- |
| i\_apb\_pready \[N-1:0]1 | Input | APB Ready |
| \[31:0] i\_apb\_prdata\[N-1:0]1 | Input | APB Read Data |
| i\_apb\_pserr\[N-1:0]1 | Input | APB Completer Error |
| o\_apb\_psel\[N-1:0]1 | Output | APB Select |
| o\_apb\_penable | Output | APB Enable |
| o\_apb\_paddr\[31:0] | Output | APB Address |
| o\_apb\_pwdata\[31:0] | Output | APB Write Data |
| o\_apb\_pwrite | Output | APB Write |
1. N=`REG_INST`
Table 4 External Enumeration Ports
These ports are only available if `ENUM_EEPROM` is NOT defined in "HOLOLINK\_def.svh"
| **Signal Name** | **Direction** | **Description** |
| ---------------------------------------- | ------------- | --------------------------------------------------------------------------------------- |
| \[47:0] i\_mac\_addr\[N-1:0]1 | Input | MAC Address for each Ethernet interface. |
| i\_board\_sn\[55:0] | Input | Board Serial Number. |
| i\_enum\_vld | Input | Enumeration Valid. Once "i\_mac\_addr" and "i\_board\_sn" is set, set and keep it to 1. |
1. N=`HOST_IF_INST`
Table 5 User Register System Initialization Ports
| **Signal Name** | **Direction** | **Description** |
| --------------- | ------------- | ------------------------------------------------------------------- |
| o\_init\_done | Output | System Initialization done. Refer to System Initialization section. |
## Sensor Interface Ports
Table 6 Sensor RX Interface Ports
These ports are only available if `SENSOR_RX_IF_INST` is defined in "HOLOLINK\_def.svh"
| **Signal Name** | **Direction** | **Description** |
| ------------------------------------------------ | ------------- | ---------------------------------------------------------------------------------------- |
| i\_sif\_rx\_clk\[N-1:0]1 | Input | Sensor RX Interface Clock. |
| o\_sif\_rx\_rst\[N-1:0]1 | Output | Sensor RX Interface Synchronous, Active-High Reset |
| i\_sif\_axis\_tvalid\[N-1:0]1 | Input | Sensor RX AXI-Stream Valid |
| i\_sif\_axis\_tlast\[N-1:0]1 | Input | Sensor RX AXI-Stream Last. |
| \[W-1:0] i\_sif\_axis\_tdata\[N-1:0]1 | Input | Sensor RX AXI-Stream Data. |
| \[X-1:0] i\_sif\_axis\_tkeep\[N-1:0]1 | Input | Sensor RX AXI-Stream Keep. Currently not supported. See Sensor RX section for more info. |
| \[Y-1:0] i\_sif\_axis\_tuser\[N-1:0]1 | Input | Sensor RX AXI-Stream User. |
| o\_sif\_axis\_tready\[N-1:0]1 | Output | Sensor RX AXI-Stream Ready |
1. N=`SENSOR_RX_IF_INST`, W=`DATAPATH_WIDTH`, X=`DATAKEEP_WIDTH`, Y=`DATAUSER_WIDTH`
Table 7 Sensor TX Interface
These ports are only available if `SENSOR_TX_IF_INST` is defined in "HOLOLINK\_def.svh"
| **Signal Name** | **Direction** | **Description** |
| ------------------------------------------------ | ------------- | -------------------------------------------------- |
| i\_sif\_tx\_clk\[N-1:0]1 | Input | Sensor TX Interface Clock. |
| o\_sif\_tx\_rst\[N-1:0]1 | Output | Sensor TX Interface Synchronous, Active-High Reset |
| o\_sif\_axis\_tvalid\[N-1:0]1 | Output | TBD |
| o\_sif\_axis\_tlast\[N-1:0]1 | Output | TBD |
| \[W-1:0] o\_sif\_axis\_tdata\[N-1:0]1 | Output | TBD |
| \[X-1:0] o\_sif\_axis\_tkeep\[N-1:0]1 | Output | TBD |
| \[Y-1:0] o\_sif\_axis\_tuser\[N-1:0]1 | Output | TBD |
| i\_sif\_axis\_tready\[N-1:0]1 | Input | TBD |
1. N=`SENSOR_TX_IF_INST`, W=`DATAPATH_WIDTH`, X=`DATAKEEP_WIDTH`, Y=`DATAUSER_WIDTH`
Table 8 Sensor Event Ports
| **Signal Name** | **Direction** | **Description** |
| --------------------- | ------------- | ---------------------------------------------------------------------------------- |
| i\_sif\_event \[15:0] | Input | Sensor Interface Event. Asynchronous. Refer to Sensor RX section for more details. |
## Host Interface Ports
Table 9 Host Interface Clock and Reset Ports
| **Signal Name** | **Direction** | **Description** |
| --------------- | ------------- | ----------------------------------------------------------------- |
| i\_hif\_clk | Input | 156.25MHz Host Interface Clock. See clocking section for details. |
| o\_hif\_rst | Output | Host Interface Synchronous, Active-High Reset. |
Table 10 Host RX Interface Ports
Connect the Host RX AXI-Streaming ports directly to Ethernet MAC RX AXI-Streaming ports.
| **Signal Name** | **Direction** | **Description** |
| ----------------------------------------------- | ------------- | ---------------- |
| i\_hif\_axis\_tvalid\[N-1:0]1 | Input | AXI-Stream Valid |
| i\_hif\_axis\_tlast\[N-1:0]1 | Input | AXI-Stream Last |
| \[W-1:0]i\_hif\_axis\_tdata\[N-1:0]1 | Input | AXI-Stream Data |
| \[X-1:0]i\_hif\_axis\_tkeep\[N-1:0]1 | Input | AXI-Stream Keep |
| \[Y-1:0]i\_hif\_axis\_tuser\[N-1:0]1 | Input | AXI-Stream User |
| o\_hif\_axis\_tready\[N-1:0]1 | Output | AXI-Stream Ready |
1. N=`HOST_IF_INST`, W=`DATAPATH_WIDTH`, X=`DATAKEEP_WIDTH`, Y=`DATAUSER_WIDTH`
Table 11 Host TX Interface Ports
Connect the Host TX AXI-Streaming ports directly to Ethernet MAC TX AXI-Streaming ports.
| **Signal Name** | **Direction** | **Description** |
| ----------------------------------------------- | ------------- | ---------------- |
| o\_hif\_axis\_tvalid\[N-1:0]1 | Output | AXI-Stream Valid |
| o\_hif\_axis\_tlast\[N-1:0]1 | Output | AXI-Stream Last |
| \[W-1:0]o\_hif\_axis\_tdata\[N-1:0]1 | Output | AXI-Stream Data |
| \[X-1:0]o\_hif\_axis\_tkeep\[N-1:0]1 | Output | AXI-Stream Keep |
| \[Y-1:0]o\_hif\_axis\_tuser\[N-1:0]1 | Output | AXI-Stream User |
| i\_hif\_axis\_tready\[N-1:0]1 | Input | AXI-Stream Read |
1. N=`HOST_IF_INST`, W=`DATAPATH_WIDTH`, X=`DATAKEEP_WIDTH`, Y=`DATAUSER_WIDTH`
## Peripheral Interface Ports
Table 12 SPI Ports
These ports are only available if `SPI_INST` is defined in "HOLOLINK\_def.svh"
| **Signal Name** | **Direction** | **Description** |
| -------------------------------------- | ------------- | ------------------------ |
| o\_spi\_csn\[N-1:0]1 | Output | Chip Select (Active Low) |
| o\_spi\_sck\[N-1:0]1 | Output | SPI Clock |
| o\_spi\_oen\[N-1:0]1 | Output | Output Enable |
| \[3:0]o\_spi\_sdio\[N-1:0]1 | Output | SDIO Output |
| \[3:0]i\_spi\_sdio\[N-1:0]1 | Input | SDIO Input |
1. N=`SPI_INST`
Table 13 I2C Ports
These ports are only available if `I2C_INST` is defined in "HOLOLINK\_def.svh"
| **Signal Name** | **Direction** | **Description** |
| ----------------------------------- | ------------- | ----------------------- |
| i\_i2c\_scl\[N-1:0]1 | Input | I2C Clock |
| i\_i2c\_sda\[N-1:0]1 | Input | I2C Data |
| o\_i2c\_scl\_en\[N-1:0]1 | Output | I2C Clock Output Enable |
| o\_i2c\_sda\_en\[N-1:0]1 | Output | I2C Data Output Enable |
1. N=`I2C_INST`
Table 14 UART ports
These ports are only available if `UART_INST` is defined in "HOLOLINK\_def.svh"
| **Signal Name** | **Direction** | **Description** |
| --------------- | ------------- | -------------------- |
| i\_uart\_rx | Input | UART Receive |
| i\_uart\_cts | Input | UART Clear To Send |
| o\_uart\_tx | Output | UART Transmit |
| o\_uart\_rts | Output | UART Request to Send |
| o\_uart\_busy | Output | UART Busy |
Table 15 GPIO Ports
| **Signal Name** | **Direction** | **Description** |
| -------------------------------- | ------------- | -------------------------------------------------------------------------------------------------------------------------- |
| i\_gpio\[N-1:0]1 | Input | GPIO In. Synchronous to “i\_apb\_clk” |
| o\_gpio\[N-1:0]1 | Output | GPIO Out. Synchronous to “i\_apb\_clk” |
| o\_gpio\_dir\[N-1:0]1 | Output | GPIO Direction. 0=GPIO Output, 1=GPIO Input. User can tri-state the GPIO pin using this port. Synchronous to “i\_apb\_clk” |
1. N=`GPIO_INST`
Table 16 Sensor Reset Port
| **Signal Name** | **Direction** | **Description** |
| ----------------------- | ------------- | ---------------------------------------------------------------------------------------- |
| o\_sw\_sen\_rst \[31:0] | Output | Register Controlled Reset. Connect to on-board sensor reset pin |
| o\_sw\_sys\_rst | Output | Register controlled self-clearing reset. Can be used to reset blocks, such as PCS block. |
Table 17 PTP Clock and Reset
| **Signal Name** | **Direction** | **Description** |
| --------------- | ------------- | --------------- |
| i\_ptp\_clk | Input | PTP Clock |
| o\_ptp\_rst | Output | PTP Reset |
Table 18 Internal PTP Port
These ports are only available if `EXT_PTP` is NOT defined in "HOLOLINK\_def.svh". PTP
module is instantiated within the HSB IP and is used to synchronize and timestamp.
| **Signal Name** | **Direction** | **Description** |
| ----------------------- | ------------- | -------------------------------------------------------------------------- |
| o\_ptp\_sec \[47:0] | Output | PTP Seconds Field per PTP1588-2019 v2 spec. Synchronous to i\_ptp\_clk |
| o\_ptp\_nanosec \[31:0] | Output | PTP Nanoseconds Field per PTP1588-2019 v2 spec. Synchronous to i\_ptp\_clk |
| o\_pps | Output | Pulse Per Second. Synchronous to i\_ptp\_clk |
Table 19 External PTP Port
These ports are only available if `EXT_PTP` is defined in "HOLOLINK\_def.svh". If the
Ethernet MAC IP has built-in PTP feature, that can be used to pass the timestamp to the
HSB IP.
| **Signal Name** | **Direction** | **Description** |
| ----------------------- | ------------- | -------------------------------------------------------------------------- |
| i\_ptp\_sec \[47:0] | Input | PTP Seconds Field per PTP1588-2019 v2 spec. Synchronous to i\_ptp\_clk |
| i\_ptp\_nanosec \[31:0] | Input | PTP Nanoseconds Field per PTP1588-2019 v2 spec. Synchronous to i\_ptp\_clk |