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Measuring power, Measuring power –2 – Altera Cyclone III FPGA Starter Kit User Manual

Page 24

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4–2

Altera Corporation

Cyclone III FPGA Starter Kit User Guide

July 2010

Measuring Power

The design used for power measurement is a replicated set of randomly
filled ROMs that feed a multiplier block and a shift register that is fed by
a signal that changes every clock cycle.

Tables 4–2

and

4–3

show the

power state which represent the percent of the full design used. As
compiled, this full design uses:

Logic elements: 22,493/24,624 (91%)

Combinational functions: 1,961/24,624 (8%)

Dedicated logic registers: 21,133/24,624 (86%)

Total registers: 21,133

Total pins: 73/216 (34%)

Total memory bits: 524,288/608,256 (86%)

Embedded Multiplier 9-bit elements: 128/132 (97 %)

Total PLLs: 1/4 (25%)

Measuring
Power

The example design is located in
<kit install>\examples\cycloneIII_3c25_start_power_demo. Configure
the FPGA with the .sof found in the directory.

1

The input clock (i_clk PIN_B9) is the 50-MHz oscillator on the
board, which generates the input clock for the reference design
through a PLL

f

For more information on configuring the FPGA, refer to

“Configuring

the FPGA Using the Quartus II Programmer” on page 2–3

.

Current sense resistors (0.010  ± 1%) are installed at locations JP6 (FPGA
core power) and JP3 (FPGA I/O power + other device I/O power). With
a digital multimeter set to mV measurement range, the resistor at location
JP6 measures the core power. The resistor at location JP3 measures the
I/O power. To measure the current being used in various configurations,
use the following steps:

Table 4–3. LEDs Power State (Resources)

Displays

LEDs

State

% of Design Used

MSB

LSB

Resources

LED4

LED3

00

25%

01

50%

10

75%

11

100%