Altera PowerPlay Early Power Estimator - Manual (Page 28)

3–14 Altera Corporation
PowerPlay Early Power Estimator For Arria GX FPGAs May 2008
PowerPlay Early Power Estimator Inputs
Figure 3–7 shows the PowerPlay Early Power Estimator spreadsheet and
the estimated power consumed by the DSP blocks in this design.
# of Instances Enter the number of instances that have the same configuration, clock frequency,
toggle percentage and register usage. This value is independent of the number of
dedicated DSP blocks being used. For example, it is possible to use four
9 × 9 simple multipliers that would all be implemented in the same DSP block in a
Arria GX device. In this case, the number of instances would be four.
Toggle % Enter the average percentage of DSP data outputs toggling on each clock cycle.
The toggle percentage ranges from 0 to 50%. Typically the toggle percentage is
12.5%. For a more conservative power estimate, you can use a higher toggle
percentage.
In addition, 50% corresponds to a randomly changing signal (since half the time the
signal changes from a 0–>0 or 1 –>1). This is considered the highest meaningful
toggle rate for a DSP block.
Reg Inputs? Select whether the input to the dedicated DSP block or multiplier block is registered
using the dedicated input registers. If the dedicated input registers in the DSP or
multiplier block are being used, select Yes. If the inputs are registered using
registers in ALMs then the value is No.
Reg Outputs? Select whether the outputs of the dedicated DSP block or multiplier block is
registered using the dedicated output registers. If the dedicated output registers in
the DSP or multiplier block are being used, select Yes. If the outputs are registered
using registers in ALMs, then the value is No.
Pipe-lined? Select whether the dedicated DSP block is pipelined.
Routing This shows the power dissipation due to estimated routing (in W).
Routing power is highly dependent on placement and routing, which is itself a
function of design complexity. The values shown are representative of routing
power based on experimentation on over 100 customer designs.
Use the Quartus II PowerPlay Power Analyzer for detailed analysis based on the
routing used in your design. This value is calculated automatically.
Block This shows the estimated power consumed by the DSP blocks in W. This value is
calculated automatically.
Total This shows the estimated power in W, based on the inputs you entered. It is the
total power consumed by DSP blocks and is equal to the routing power and the
block power. This value is calculated automatically.
User Comments Enter any comments. This is an optional entry.
Table 3–4. DSP & Multiplier Section Information (Part 2 of 2)
Column Heading Description