AGL015 MICROSEMI [Microsemi Corporation], AGL015 Datasheet - Page 35

• Manufacturer Part Number: AGL015
• Description: IGLOO Low Power Flash FPGAs with Flash*Freeze Technology
• Manufacturer: MICROSEMI [Microsemi Corporation]

Guidelines
Toggle Rate Definition
A toggle rate defines the frequency of a net or logic element relative to a clock. It is a percentage. If the
toggle rate of a net is 100%, this means that this net switches at half the clock frequency. Below are
some examples:
Enable Rate Definition
Output enable rate is the average percentage of time during which tristate outputs are enabled. When
nontristate output buffers are used, the enable rate should be 100%.
Table 2-23 • Toggle Rate Guidelines Recommended for Power Calculation
Table 2-24 • Enable Rate Guidelines Recommended for Power Calculation
Component
α
α
Component
β
β
β
1
2
3
1
2
•
•
The average toggle rate of a shift register is 100% because all flip-flop outputs toggle at half of the
clock frequency.
The average toggle rate of an 8-bit counter is 25%:
– Bit 0 (LSB) = 100%
– Bit 1
– Bit 2
– …
– Bit 7 (MSB) = 0.78125%
– Average toggle rate = (100% + 50% + 25% + 12.5% + . . . + 0.78125%) / 8
= 50%
= 25%
Toggle rate of VersaTile outputs
I/O buffer toggle rate
I/O output buffer enable rate
RAM enable rate for read operations
RAM enable rate for write operations
R ev i si o n 1 9
Definition
Definition
IGLOO Low Power Flash FPGAs
Guideline
Guideline
12.5%
12.5%
100%
10%
10%
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