Revision 13 3-1
3 – Pin Descriptions
Supply Pins
GND Ground
Ground supply voltage to the core, I/O outputs, and I/O logic.
GNDQ Ground (quiet)
Quiet ground supply voltage to input buffers of I/O banks. Within the package, the GNDQ plane is
decoupled from the simultaneous switching noise originated from the output buffer ground domain. This
minimizes the noise transfer within the package and improves input signal integrity. GNDQ must always
be connected to GND on the board.
VCC Core Supply Voltage
Supply voltage to the FPGA core, nominally 1.5 V. VCC is required for powering the JTAG state machine
in addition to VJTAG. Even when a device is in bypass mode in a JTAG chain of interconnected devices,
both VCC and VJTAG must remain powered to allow JTAG signals to pass through the device.
VCCIBx I/O Supply Voltage
Supply voltage to the bank's I/O output buffers and I/O logic. Bx is the I/O bank number. There are up to
eight I/O banks on low power flash devices plus a dedicated VJTAG bank. Each bank can have a
separate VCCI connection. All I/Os in a bank will run off the same VCCIBx supply. VCCI can be 1.5 V,
1.8 V, 2.5 V, or 3.3 V, nominal voltage. Unused I/O banks should have their corresponding VCCI pins tied
to GND.
VMVx I/O Supply Voltage (quiet)
Quiet supply voltage to the input buffers of each I/O bank. x is the bank number. Within the package, the
VMV plane biases the input stage of the I/Os in the I/O banks. This minimizes the noise transfer within
the package and improves input signal integrity. Each bank must have at least one VMV connection, and
no VMV should be left unconnected. All I/Os in a bank run off the same VMVx supply. VMV is used to
provide a quiet supply voltage to the input buffers of each I/O bank. VMVx can be 1.5 V, 1.8 V, 2.5 V, or
3.3 V, nominal voltage. Unused I/O banks should have their corresponding VMV pins tied to GND. VMV
and VCCI should be at the same voltage within a given I/O bank. Used VMV pins must be connected to
the corresponding VCCI pins of the same bank (i.e., VMV0 to VCCIB0, VMV1 to VCCIB1, etc.).
VCCPLA/B/C/D/E/F PLL Supply Voltage
Supply voltage to analog PLL, nominally 1.5 V.
When the PLLs are not used, the Designer place-and-route tool automatically disables the unused PLLs
to lower power consumption. The user should tie unused VCCPLx and VCOMPLx pins to ground.
Microsemi recommends tying VCCPLx to VCC and using proper filtering circuits to decouple VCC noise
from the PLLs. Refer to the PLL Power Supply Decoupling section of the "Clock Conditioning Circuits in
IGLOO and ProASIC3 Devices" chapter of the ProASIC3 FPGA Fabric User’s Guide for a complete
board solution for the PLL analog power supply and ground.
There is one VCCPLF pin on ProASIC3 devices.
VCOMPLA/B/C/D/E/F PLL Ground
Ground to analog PLL power supplies. When the PLLs are not used, the Designer place-and-route tool
automatically disables the unused PLLs to lower power consumption. The user should tie unused
VCCPLx and VCOMPLx pins to ground.
There is one VCOMPLF pin on ProASIC3 devices.
VJTAG JTAG Supply Voltage
Low power flash devices have a separate bank for the dedicated JTAG pins. The JTAG pins can be run
at any voltage from 1.5 V to 3.3 V (nominal). Isolating the JTAG power supply in a separate I/O bank
gives greater flexibility in supply selection and simplifies power supply and PCB design. If the JTAG
interface is neither used nor planned for use, the VJTAG pin together with the TRST pin could be tied to
GND. It should be noted that VCC is required to be powered for JTAG operation; VJTAG alone is
