13.33.108 pin_assign

Use to either assign the named pin to the specified port or assign attributes to the specified port. This command has two syntax formats. The one you use depends on what you are trying to do. The first syntax format assigns the named pin to the specified port and supports all families. The second one assigns attributes to the specified port but supports only the ProASIC3, Axcelerator, SX-A, RTSX-S, and eX families.

pin_assign [-nofix] -port portname -pin pin_number

pin_assign -port portname [-iostd value][-iothresh value][-outload value][-slew value][-res_pull value]

Arguments

-nofix

Unlocks the pin assignment (by default, assignments are locked).

-port portname

Specifies the name of the port to which the pin is assigned.

-pin pin_number

Specifies the alphanumeric number of the pin to assign.

-iostd value

Sets the I/O standard for this pin. Choosing a standard allows the software to set other attributes such as the slew rate and output loading. If the voltage standard used with the I/O is not compatible with other I/Os in the I/O bank, then assigning an I/O standard to a port will invalidate its location and automatically unassign the I/O. The following table shows the acceptable values for the supported devices:

Use the I/O Standards table to see which I/O standards can be applied to each family:

Table 13-51. I/O Standards
I/O StandardIGLOOFusionProASIC3AxceleratorRTSX-SSX-A

CMOS

————

X

—

CUSTOM

————

X

X

GTLP25

IGLOOe

only

X

ProASIC3E and ProASIC3L only

X

——

GTLP33

IGLOOe

only

X

ProASIC3E and ProASIC3L only

———

GTL33

IGLOOe

only

X

ProASIC3E and ProASIC3L only

X

——

GTL25

IGLOOe

only

X

ProASIC3E and ProASIC3L only

X

——

HSTL1

IGLOOe

only

X

ProASIC3E and ProASIC3L only

X

——

HSTLII

IGLOOe

only

X

ProASIC3E and ProASIC3L only

———

LVCMOS33

X

X

X

———

LVCMOS25

IGLOOe

only

X

X

X

——

LVCMOS25_50

X

X

X

———

LVCMOS18

X

X

X

X

——

LVCMOS15

X

X

X

X

——

LVCMOS12

X

—

ProASIC3L only

———

LVTTL

X

X

X

X

X

X

TTL

X

X

X

X

X

X

PCI

X

X

X

X

X

X

PCIX

X

X

X

X

——

SSTL2I

IGLOOe

only

X

ProASIC3E and ProASIC3L only

X

——

SSTL2II

IGLOOe

only

X

ProASIC3E and ProASIC3L only

X

——

SSTL3I

IGLOOe

only

X

ProASIC3E and ProASIC3L only

X

——

SSTL3II

IGLOOe

only

X

ProASIC3E and ProASIC3L only

X

——
Note: The LVDS and LVPECL I/O standards cannot be set through a script.

-iothresh value

Sets the compatible threshold level for inputs and outputs. The default I/O threshold is based upon the I/O standard. You can set the I/O Threshold independently of the I/O specification in the PinEditor tool by selecting CUSTOM in the I/O Standard cell. The following table shows the acceptable values for the supported devices (SX-A, RTSX-S, and eX):
ValueDescription

CMOS

RTSX-S devices only. An advanced integrated circuit (IC) manufacturing process technology for logic and memory, characterized by high integration, low cost, low power, and high performance. CMOS logic uses a combination of p-type and n-type metal-oxide-semiconductor field effect transistors (MOSFETs) to implement logic gates and other digital circuits found in computers, telecommunications, and signal processing equipment.

LVTTL

(Low-Voltage TTL) A general purpose standard (EIA/JESDSA) for 3.3V applications. It uses an LVTTL input buffer and a push-pull output buffer.

PCI

A computer bus for attaching peripheral devices to a computer motherboard in a local bus. This standard supports both 33 MHz and 66 MHz PCI bus applications. It uses an LVTTL input buffer and a push-pull output buffer. With the aid of an external resistor, this I/O standard can be 5V-compliant for most families, excluding IGLOO, ProASIC3, SmartFusion and Fusion families.

Note: The -iothresh attribute is also referred to as "Loading" in some families.

-slew value

Sets the output slew rate. Slew control affects only the falling edges. Rising edges are not affected. This attribute is only available for LVTTL, PCI, and PCI outputs. For LVTTL, it can either be high or low. For PCI and PCIX, it can only be set to high. The following table shows the acceptable values for the supported devices (IGLOO, ProASIC3, SmartFusion, Fusion, ProASICPLUS, ProASIC, Axcelerator, RTAX-S, eX, and SX-A):

ValueDescription

high

Sets the I/O slew to high

low

Sets the I/O slew to low

-res_pull value

Allows you to include a weak resistor for either pull-up or pull-down of the input buffer. The following table shows the acceptable values for the supported devices (IGLOO, ProASIC3, SmartFusion, Fusion, ProASICPLUS, ProASIC, Axcelerator, RTAX-S, eX, and SX-A):

ValueDescription

up

Includes a weak resistor for pull-up of the input buffer

down

Includes a weak resistor for pull-down of the input buffer

none

Does not include a weak resistor

-out_load value

Indicates the output-capacitance value based on the I/O standard selected. This option is not available in software. This attribute determines what Timer will use as the loading on the output pin and applies only to outputs. You can enter a capacitive load as an integral number of picofarads (pF). The default is 35pF. This attribute is available only for the following devices: ProASIC3, SmartFusion, Fusion, Axcelerator, SX-A, RTSX-S, and eX.