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304 www.xilinx.com Development System Reference Guide
Chapter 18: CPLDfit
R
–optimize (Optimize Logic for Density or Speed)
-optimize density|speed
This -optimize option directs CPLDfit to optimize the design for density or speed.
Optimizing for density results in a slower speed but uses resource sharing to allow more
logic to fit into a device. Optimizing for speed uses less resource sharing but flattens the
logic, which results in fewer levels of logic (faster). Density is the default argument for this
option.
–p (Specify Xilinx Part)
-p part
The -p option specifies the Xilinx product family; <part> is in the form of device-
speedgrade-package (for example, XC2C512-10-FT256).
If only a product family is entered (for example, XPLA3), CPLDfit iterates through all
densities until a fit is found.
–pinfbk (Use Pin Feedback)
The XC9500 architecture allows feedback into the device through the I/O pin. The -pinfbk
option turns this feedback functionality on. This option is on by default.
Architecture Support: XC9500
–power (Set Power Mode)
-power [std|low|auto]
The -power option sets the default power mode of macrocells. This option can be
overridden if a macrocell is explicitly assigned a power setting. The std setting is for
standard high speed mode. The low setting is for low power mode (at the expense of
speed). The auto setting allows CPLDfit to choose the std or low setting based on the timing
constraints. The default setting for this option is std.
Note:
This option is available for XC9500/XL/XV devices.
–pterms (Number of Pterms to Use During Optimization)
-pterms [limit:1,90]
The -pterms option specifies the maximum number of product terms for a single equation.
The higher this value, the more product term resources a single equation may use, possibly
limiting the number of equations allowed in a single function block. The maximum limit
varies with each CPLD architecture. The limits are as follows (default in parenthesis):
XC9500 = 90 (25)
XC9500XL/XV = 90 (25)
CoolRunner XPLA3 = 48 (36)
CoolRunner-II = 56 (36)