I/O Software Control in Low-Power Flash Devices
v1.1
8 - 11
Compiling the Design
During Compile, a PDC I/O constraint file can be imported along with the netlist file. If only the
netlist file is compiled, certain I/O assignments need to be completed before proceeding to Layout.
All constraints that can be entered in PDC can also be entered using ChipPlanner, I/O Attribute
Editor, and PinEditor.
There are certain rules that must be followed in implementing I/O register combining and the I/O
DDR macro (refer to the I/O Registers section of the handbook for the device that you are using
or disable I/O register combining by using the PDC command set_io portname –register yes|no
in the I/O Attribute Editor or selecting a check box in the Compile Options dialog box (see
Figure 8-8). The Compile Options dialog box appears when the design is compiled for the first time.
It can also be accessed by choosing Options > Compile during successive runs. I/O register
combining is off by default. The PDC command overrides the setting in the Compile Options dialog
box.
Understanding the Compile Report
The I/O bank report is generated during Compile and displayed in the log window. This report lists
the I/O assignments necessary before Layout can proceed.
When Designer is started, the I/O Bank Assigner tool is run automatically if the Layout command is
executed. The I/O Bank Assigner takes care of the necessary I/O assignments. However, these
assignments can also be made manually with MVN or by importing the PDC file. Refer to the
The I/O bank report can also be extracted from Designer by choosing Tools > Report and setting the
Report Type to IOBank.
This report has the following tables: I/O Function, I/O Technology, I/O Bank Resource Usage, and I/O
Voltage Usage. This report is useful if the user wants to do I/O assignments manually.
Figure 8-8 Setting Register Combining During Compile