AN8087 - Lattice Semiconductor Corporation

July 2011 Application Note AN8087
Prerequisite
• Lattice Diamond ® design software version 1.3
Introduction
Large FPGAs usually have a large number of package pins; these pins are comprised of multiple pin types or pin
functions to facilitate different design uses. The information about how these pins are used or assigned is also
important for various aspects of a design. Lattice Diamond design software provides the ability for a user to generate
a list of all pins and the associated usage information for each pin into a standard format that can be used as
follows:
Document and check pin assignments and pin usage
Document comprehensive pin information for design planning
Exchange pin assignment information with board/schematic designer or other design software and hardware
tools
Design documentation
This application note explains:
How to export the pins and their usage information from your design into a well-formatted text file called a Pin
Layout File
The content and format of a Pin Layout File
How to import a modified Pin Layout File back into Lattice Diamond design software
How to export a Pinout File
Pin Layout File
There are two sections in a Pin Layout File: a header and a body.
The Header
The header includes the following lines, with each line starting with “#”:
The generator of the Pin Layout File (i.e., Lattice Diamond and its version number)
The time and date the file was generated
The design/project name
The device used for the design
The package type of the device
The speed grade of the device
Figure 1 shows an example of the header exported.
Using Lattice Diamond
Pin Layout Files and Pinout Files
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Lattice Semiconductor Pin Layout Files and Pinout Files
Figure 1. Example of the Header Exported
#Pin Layout Report file generated by Lattice Diamond Version 1.3.71
#Generated at Tue May 31 14:08:25 2011
#DESIGN = top
#DEVICE = LFE3-70EA
#PACKAGE = FPBGA484
#SPEEDGRADE = 7
The Body
The body of the exported file includes all package pins and optionally their usage information.
The first line of the body includes the field names for the columns of data which are exported to the Pin Layout File.
The fields may vary by device. All fields for a chosen device can be seen in the Spreadsheet View, Port Assignments
and Pin Assignments tabs in the Spreadsheet View in Lattice Diamond. Some commonly used fields that
can be selectively exported for all devices include:
Pin number
Pin name
Pin function
Bank number
Pin type
I/O type, or I/O standard of the pin that was assigned
Signal name: the design port/signal that was assigned to the pin, if available
Direction: the direction of the signal/port that was assigned to the pin
Some device-specific fields are:
Pullmode
Drive
Slewrate
PCIClamp
Opendrain
For detailed information and an explanation of each field, please refer to the Lattice Diamond User Guide, Lattice
Diamond online help, or the related device data sheet
Beneath the first line in the Pin Layout File are the lines of information for all package pins with one pin per row.
Each pin/row starts with its pin number, followed by user-selected pin usage information or fields. Each field occupies
a column, and all fields are separated by a user-defined delimiter.
User-selectable delimiters can include commas (,), semicolons (;), spaces ( ), and tabs ().
The order of all exported fields (except the pin number) can be manually controlled when exporting the Pin Layout
File through a graphical user interface, as shown in Figure 3.
Figure 2 shows a few lines from the body of a Pin Layout File. Note that due to the limited space, not all columns
from the example are shown here.
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Using Lattice Diamond
Lattice Semiconductor Pin Layout Files and Pinout Files
Figure 2. Example of the Body Exported
# There are 19 columns in the table
Pin Number, Pad Name, Function, IO Bank Number, Signal Name, Direction, Trace
T17, PR61E_D, RLM1_GPLLT_IN_B, 3, , , 7426.660000, , , , , , , , , , , ,
V20, PR61E_B, RLM1_GPLLT_FB_B, 3, , , 10963.890000, , , , , , , , , , , ,
R17, PR61E_C, RLM1_GPLLT_IN_A, 3, CLK, Input, 6796.230000, LVCMOS33, OFF,
V21, PR61E_A, RLM1_GPLLT_FB_A, 3, , , 10936.450000, , , , , , , , , , , ,
Figure 3. Export Pin Layout File User Interface
Exporting Pin Layout Files
The Pin Layout File can be exported at any time during a project cycle, but it is recommended that you do so at one
of the following three stages:
1. Before Synthesis or Translation
At this stage, all design information such as design ports/signals, pin assignments, etc., are not available
and therefore, cannot be exported. A Pin Layout File exported at this time includes all physical pin information
for all pins of the device selected in the project. A file exported at this time can, for example, be used to
understand the pin-related information of the device, or can be used for early pin assignment and usage
planning.
A Pin Layout File exported at this stage can be considered as a device-specific pin information file.
2. Pre- or Post-MAP
At this stage, you may have already made some pin assignments, defined I/O standards, and so on. You
can export these user-defined pin assignments along with all physical pin information into a second Pin
Layout File. This exported file can be shared with, for example, a schematic or board designer for pin
assignment review and changes. At a later time, the modified Pin Layout File can be imported back into
Lattice Diamond design software to update the pin assignments.
A Pin Layout File exported at this stage can be considered as a design-specific pin usage exchange file.
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Using Lattice Diamond
Lattice Semiconductor Pin Layout Files and Pinout Files
3. Post-PAR
At this stage, if PAR is completed successfully, all design ports/signals are assigned, either by you or by
PAR. If the PAR result is desirable, a third Pin Layout File can be exported. This file will include the final pin
assignment information and can be handled over to, for example, the board designer as the pin assignment
signoff. The exported file at this stage can also be used for final design documentation purposes.
A Pin Layout File exported at this stage can be considered as a pin assignment sign-off file.
To export a Pin Layout File at any time, follow these steps:
1. In Lattice Diamond, open Spreadsheet View.
2. Select the pull-down menu File > Export > Pin Layout File …
3. In the Export Pin Layout File GUI, specify the file name as well as the columns and column delimiters you
wish to use in your Pin Layout File (refer to Figure 3).
For details, please refer to the Lattice Diamond User Guide or the Lattice Diamond online help
Importing Pin Layout Files
The pin assignments in the Pin Layout File may be modified outside of the Lattice Diamond environment by you or
a schematic/board designer using a text editor or a spreadsheet editor. The modified Pin Layout File can then be
imported back into Lattice Diamond design software to easily and quickly update the current pin assignments.
Though you are free to import such a file at any time after the Translation process, there are some recommendations
that you should follow:
Since any committed pin assignment change done in Spreadsheet View will reset the Process flow, you should
import a Pin Layout File after Synthesis/Translation and before MAP whenever possible.
You should import a Pin Layout File into a project from where the Pin Layout File was exported. This will ensure
the device used in both the file and the project are the same, and ports and signals defined in the file are synchronized
with the project.
You should not change any field names on the first line of the body, otherwise a new name may not be recognized
and the import process might fail. Specifically, you should not change the name of the fields “Pin_Number”
and “Signal_Name”.
You may change port/signal names, or add new ports/signals to the file that will be imported. If you do so, make
sure the new names exist in the project (you can check this through the Spreadsheet View, Port Assignments
tab). Remember any signal/port that was defined in the Pin Layout File but does not exist in the project will not be
imported and will be ignored.
If you migrate a project to a new device, and the new device is pin migration compatible with the original device,
you can import the Pin Layout File which was exported from the original project that used the old device. When
doing this type of change, please make sure the “DEVICE” line in the header is changed to match the name of
the new device prior to importing the Pin Layout File; otherwise the import process will fail.
To import a Pin Layout File, the Translation process must complete successfully.
In Lattice Diamond design software, follow these steps:
1. In Lattice Diamond design software, open Spreadsheet View.
2. Select the pull-down menu File > Export > Pin Layout File …
3. Specify the name of the file to be imported and the column delimiter used in the file.
For details, please refer to the Lattice Diamond User Guide or the Lattice Diamond design software online help.
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Using Lattice Diamond
Lattice Semiconductor Pin Layout Files and Pinout Files
Pinout File
In addition to a Pin Layout File, you can also export a Pinout File for a specific device in Lattice Diamond design
software. A device’s Pinout File (CSV) can be downloaded from the Lattice web site, or the information can be
found in the device data sheet. Now you can also generate a Pinout File in Lattice Diamond design software.
Unlike the Pin Layout File, for which you have multiple options to control the content and the format, a device Pinout
File has the following characteristics:
The content of a device Pinout File is device-specific and contains no information about a design.
A Pinout File can be exported at any time, but the content is always the same.
A Pinout File is always “comma separated”.
A Pinout File cannot be imported into Lattice Diamond design software.
A Pinout File contains the following two sections:
– A header, which includes the generator information (i.e., Lattice Diamond version number), the generation
time, the device name and the package type
– A body, or pin information, which includes the following fields in the fixed order and may vary per device:
- Index number
- Pin/ball function
- Pin type
- Bank number
- Dual function names
- Differential definition
- Pin number
- DQS, and
- I/O grouping
To export a Pinout File, follow these steps:
1. In Lattice Diamond, open Spreadsheet View.
2. Select the pull-down menu File > Export > Pin Out File …
3. Specify the filename and location to save the file.
For details, please refer to the Lattice Diamond User Guide or Lattice Diamond online help.
In Lattice Diamond design software version 1.3, only “bonded” pads (i.e., those pads bonded out to package pins)
will be exported into a Pinout File; in the future releases “unbonded” pads will be included.
Lattice CSV File
For legacy design support purposes, Lattice Diamond 1.3 still supports Lattice CSV File import and export. Lattice
CSV File support may be removed in future software releases, thus it is strongly recommended to discontinue use
of Lattice CSV Files.
For detailed information about Lattice CSV Files, please refer to the Lattice Diamond User Guide, or Lattice Diamond
online help.
Additional Information
For additional information about Lattice Diamond design software, please visit www.latticesemi.com, or send an
email to sw_mktg@latticesemi.com.
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Using Lattice Diamond
Lattice Semiconductor Pin Layout Files and Pinout Files
Technical Support Assistance
Hotline: 1-800-LATTICE (North America)
+1-503-268-8001 (Outside North America)
e-mail: techsupport@latticesemi.com
Internet: www.latticesemi.com
Revision History
Date Version Change Summary
July 2011 01.0 Initial release.
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