CAM Table Configuration - 2025.1 English - UG1308

If the Show More Detail box is checked, more information is displayed per table (key width, resp width, num entries, num masks, and mode).

Ram Style

Selects the RAM style to be applied for each CAM instance. The options are:

Global Setting

Uses the global CAM RAM style as defined under Global Setting for Tables.

Block RAM

Table implemented in Block RAM.

Ultra RAM

Table implemented in URAM.

DDR

Table implemented in Double Data Rate memory.

HBM

Table implemented in High Bandwidth Memory (only supported for BCAM).

Clock Source

Sets the clock source to be either CAM Memory clock or AXI4-Stream clock. The CAM Memory clock allows for the CAMs to run at a higher rate (up to 600 MHz) to reduce resource utilization.

HW Update

This tick box appears if a Versal part is selected, Ram Style is set to either DDR or HBM and Mode is set to BCAM.

If this box is unchecked, table management (inserts/deletes/updates) is performed by software and requires a shadow memory. The performance of the inserts/deletes/updates depends on the processor.

If this box is checked, no shadow memory is required and table management performance is independent of the processor, but extra hardware resources are needed. However, insert/delete/update operations are still triggered by software in hardware mode.

Cache Entries

The drop-down menu beside Cache Entries appears if a Versal part is selected, Ram Style is set to either DDR or HBM and Mode is set to BCAM. Cache support can be disabled by selecting NONE.

Lookup rate

The lookup rate of a CAM table can be individually tuned to the required value.

Note: The lookup rate cannot exceed the configured packet rate.

Note: If the selected configuration results in too many memory units to be generated by the CAM, an error appears in the Vivado console as shown in the following figure. Clear this error before proceeding.

Figure 1. Too Many Memory Units Error