1.9 User I/O and Clock Pins

The following table lists the unused I/O and clock pins in a SmartFusion2/IGLOO2 device.

Table 1-17. Recommendations for Unused I/O and Clock Pins

I/O

Unused Condition

Remarks

MSIO

Libero-Defined DNC1

Internal weak pull-up is available

MSIOD

DDRIO

Programming SPI pins

Crystal oscillator pins

Must be left floating and must not connect to ground (VSS)

Internal weak nominal 50 kΩ pull-up to VPP

Note:
  1. Libero configures unused user I/O (MSIO, MSIOD, and DDRIO) as: input buffer disabled, output buffer tristated with weak pull-up.