Efinix Titanium - Dynamic Voltage Support

Titanium Interfaces User Guide
Dynamic Voltage Support
Titanium HVIO I/O banks support dynamic voltage shifting. This feature lets you change
the voltage to the I/O bank during user mode. There are two methods for changing the
voltage:
• If you are not using 1.8 V at all, you can simply change the voltage at any time. For
example, you can change from 3.3 V to 2.5 V and then back to 3.3 V.
• If you are changing the voltage to 1.8 V, you must enable an option in the Interface
Designer (which creates a mode select pin) and follow the timing requirements for the
voltage change as described below.
To enable the option in the Interface Designer:
1. Choose Device Setting > I/O Banks.
2. Turn on Enable Dynamic Voltage.
3. Save.
4. Add the mode select pin (<bank>_MODE_SEL) to your RTL design.
5. Recompile.
When switching the voltage, pull down the voltage to 1.8 V for at least 1 ms before pulling
the mode select signal high. Similarly, wait for at least 1 ms after releasing the mode select
signal before changing the voltage back to the higher level.
Figure 8: VCCIO Switching Waveform (2.5, 3.0, or 3.3 V to 1.8 V )
VCC
VCCIO33
<bank>_MODE_SEL
Where <bank> is the bank name.
For example, for bank BR the pin
name is BR_MODE_SEL.
VDD
2.5, 3.0, or 3.3 V 2.5, 3.0, or 3.3 V
1.8 V
≥ 1 ms
The I/O performance
cannot be guaranteed
during this period.
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