ep1m120 Altera Corporation, ep1m120 Datasheet - Page 47

• Manufacturer Part Number: ep1m120
• Description: Programmable Logic Device Family
• Manufacturer: Altera Corporation

Mercury Programmable Logic Device Family Data Sheet
Programmable Speed/Power Control
TM
Mercury device ESBs offer the Turbo Bit
option, a high-speed mode that
supports fast operation on an ESB-by-ESB basis. When high speed is not
required, the Turbo Bit option can be turned off to reduce power
dissipation by up to 50%. ESBs that run at low power incur a nominal
timing delay adder. An ESB that is not used will be powered down so it
does not consume DC current.
Designers can program each ESB in the Mercury device for either high-
speed or low-power operation. As a result, speed-critical paths in the
design can run at high speed, while the remaining paths operate at
reduced power.
I/O Structure
The IOE in Mercury devices contains a bidirectional I/O buffer and three
registers for a complete embedded bidirectional IOE. The IOE contains
individual input, output, and output enable registers. The input register
can be used for external data requiring fast setup times. The output
register can be used for data requiring fast clock-to-output performance.
The output enable (OE) register can be used for fast clock-to-output enable
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timing. The Quartus II software automatically duplicates a single OE
register that controls multiple output or bidirectional pins.
For normal bidirectional operation, the input register can have its own
clock input separate from the OE and output registers. The OE and output
register share the same clock source. Each register can have its own clock
enable signal from local interconnect in the associated LAB, fast global
signals, or row global signals.
Altera Corporation
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