Dedicated I/O Pins

Both the device families have a dedicated bank of I/Os. These I/Os are used for JTAG, SPI, and dedicated functions and pins supporting from 3.3 V to 1.8 V (Nominal) operation using the dedicated VDDI3 bank. Single-ended CMOS/TTL receiver input and output drivers are fixed in the device as listed in the following table.

Table 1. Dedicated I/Os—Fixed Settings
Dedicated I/Os Signal Direction Hot Swap Pull Mode Clamp Hysteresis Drive Strength
SCK BIDI Yes OFF OFF ON n/a
SS BIDI Yes OFF OFF ON n/a
SDO OUT Yes OFF OFF OFF 8 mA
TDO OUT Yes OFF OFF OFF 12 mA
TMS IN No pull up OFF ON n/a
TDI IN No pull up OFF ON n/a
TCK IN Yes OFF OFF ON n/a
TRSTB IN No pull up OFF ON n/a
DEVRST_N IN No pull up OFF ON n/a
RESERVED IN No pull up OFF ON n/a
SDI IN Yes OFF OFF ON n/a
IO_CFG_INTF IN Yes OFF OFF ON n/a
SPI_EN IN Yes OFF OFF ON n/a
Note: These signals cannot be altered or programmed with Libero SoC.

The five dedicated inputs—TDI, TMS, TRSTB, DEVRSTB, and RESERVED—do not support hot swap. The SDI pin does not have an on-chip weak pull-up due to the following reasons:

For more information, see PolarFire FPGA and PolarFire SoC FPGA Programming User Guide.