After you have entered the required clock for the design, the remaining resources must be estimated. The resource pages appear in the navigation pane view under the Estimation section.
PDM organizes resources into the following categories:
- PS & VCU
- This shows the Processing Subsystem with the MPSoC Processing Subsystem (PS) which has quad-core Arm® Cortex-A53 and dual-core Arm Cortex®-R5F along with a Mali™ 400 MP GPU. You can configure the Video Codec Unit (VCU) and System Monitors on this page. VCU block is only supported for K26 devices for this release of PDM.
- Clock
- The Clock page covers power estimates of clock networks and related clock
generation circuits. PDM uses explicit clocks rather
than arbitrary clock frequency specification. You should define each clock
using the Clocking Wizard before it
can be used on any other sheet. Although it requires some setup, an explicit
clock has certain advantages:
- Identification
- The unique clock name allows it to be distinguished from other clocks, particularly those with an identical frequency.
- Ease-of-use
- Modifying a clock definition propagates changes to all sheets where the clock is used.
- Consistency
- A clock's fanout is automatically accumulated from all sheets where it is used, resulting in a consistent estimation of clock network power on the Clock page.
- Voltage & Current Requirements
- This table lists all the power rail requirements for the carrier card.
Both current and voltage requirements are specified.Tip: Kria estimation differs from a typical power estimation where the MPSoC rails would be displayed. The SOM has a pre-connected power delivery and so PDM simply shows the required inputs. PDM also has DRCs to ensure that the estimated power does not exceed the current limits of the K26 SOM power delivery.
- Environment
- Lets you either force the junction temperature to a fixed value or specify
the maximum ambient and effective Theta-JA for the thermal solution
(obtained from thermal simulation).Recommended: Worst case junction temperature must be used until Theta-JA is obtained from thermal simulations. For more details see Kria K26 SOM Thermal Design Guide (UG1090).
- Thermal Loading
- This table shows the power dissipated on the device. For Kria, it also shows the other external
peripherals such as DDRs, power regulators, and boot devices available on
SOM. The values in the thermal loading table must be used as inputs to a
third-party thermal simulation.Figure 2. K26 SOM Flotherm Compact Model
- Logic
- This page allows you to enter the logic resource usage and toggle rates.
The available K26 SOM and supported Versal
devices resources and usage are displayed in the usage table.Figure 3. Logic
- Block RAM and UltraRAM
- Allows the Block RAM and URAM usage to be entered.
- DSP
- The usage of DSP blocks along with the clock rate and expected toggle rate can be entered here.
- I/O
- The I/O page, lists all the available interfaces from both the processing
subsystem (DDR4, PSMIO, and GTR) and the PL (PL IOs, and GTHs). The
Power Summary &
Utilization table shows the available interfaces
based on the Kria K26 SOM and the 2 x 240 pin
connectors to ensure that designs are kept within the K26 SOM limits.Figure 4. I/O Power Summary and Usage
For the programmable logic (PL) I/Os, the Kria K26 SOM gives access to six banks: three High Density (HD) banks and three High Performance (HP) banks. PDM allows selection of both VCCO voltage for each of these banks as well as the supported I/O standards that correspond to the VCCO voltage selected.
Figure 5. Programmable Logic for IOs
The previous image shows that you can only select 1.8V IOSTANDARDs based on the 1.8V entered for the HDC VCCO. The power estimated for the PL I/Os will also be reflected as a carrier card current and voltage requirement as you need to provide these VCCOs values. The VCCO voltage range is also displayed.
Figure 6. Voltage and Current Requirements
- Hard IP Blocks
- This page allows definition of the desired PCIe setup.Figure 7. PCIe Block Power Estimation