The UltraRAM sheet covers power estimates of the dedicated 288 Kb UltraRAM block. The UltraRAM in Versal® ACAP has more flexibility than UltraScale+™ . The Add Memory IP wizard does not yet support UltraRAM. So, the resources must be estimated or calculated manually. The settings that define UltraRAM structure include the following:
- Cascade Group Size
- UltraRAM blocks support cascading to create larger memory arrays while reducing the overall power by enabling only one UltraRAM of a cascade at a time. Example: 20 UltraRAM blocks with a Cascade Group Size of 4 represents 20/4 = 5 sets of cascaded UltraRAM of 4 blocks each. If there is no cascading, use 1 as the value of cascade group size. The Cascade Group Size applies to vertical cascading, increasing array depth.
- The optional UltraRAM pipeline registers are IREG_PRE (input) or REG_CAS (cascade). The default value is Cascade Group Size divided by 3. If there is no UltraRAM cascading, only IREG_PRE can be used which corresponds to a Latency of 1.
- Chooses between
URAM288 (no ECC)and
The following settings define the UltraRAM activity:
- Sleep Rate
- The percentage of time the UltraRAM SLEEP input pin is asserted. The value of Auto is also supported for Automatic Sleep Mode.
- Average Inactive Cycles
- The average number of consecutive inactive cycles when in Sleep Mode. The minimum value is > 10 or the Cascade Group Size minus 2.
- Input Toggle Rate
- The average toggle rate of the data inputs (DIN) for both ports A and B.
- Output Toggle Rate
- The average toggle rate of the data outputs (DOUT) for both ports A and B.
- Clock (MHz)
- Clock frequency of the UltraRAM or UltraRAM module.
Following are the values specified for the UltraRAM ports A and B:
- Data Width
- Specify the exact data width if less than the maximum 72 bits.
- Enable Rate
- The percentage of time the UltraRAM is enabled.
- Write Enable
- The percentage of time the write enable input is asserted, independently of the Enable Rate. The write enable pins are the UltraRAM RDB_WR_A and RDB_WR_B pins.
Note: When you specify Enable Rate and Sleep Rate, for each of the ports A and B, the sum of (Enable Rate / Cascade Group Size) and Sleep Rate must not exceed 100%.