left_right_leds.ucf

xilinx的SPARTAN-3E入门开发板实例 根据官方公布的led移动范例改写。 原范例仅提供了源代码、烧写文件以及dos窗口下使用的烧写bat文件。 本实例采用了ise7.1i创建

# Constraints for reference design 'left_right_leds'.
#
# Revision C of the Spartan-3E Starter Kit.
#
# Ken Chapman - Xilinx Ltd - November 2005
# Revised 20th February 2006
#
# Period constraint for 50MHz operation
#
NET "clk" PERIOD = 20.0ns HIGH 50%;
#
#
# soldered 50MHz Clock.
# 
NET "clk" LOC = "C9" | IOSTANDARD = LVTTL;
#
#
# Simple LEDs 
# Require only 3.5mA. 
#
NET "led<0>" LOC = "F12" | IOSTANDARD = LVTTL | SLEW = SLOW | DRIVE = 4;
NET "led<1>" LOC = "E12" | IOSTANDARD = LVTTL | SLEW = SLOW | DRIVE = 4;
NET "led<2>" LOC = "E11" | IOSTANDARD = LVTTL | SLEW = SLOW | DRIVE = 4;
NET "led<3>" LOC = "F11" | IOSTANDARD = LVTTL | SLEW = SLOW | DRIVE = 4;
NET "led<4>" LOC = "C11" | IOSTANDARD = LVTTL | SLEW = SLOW | DRIVE = 4;
NET "led<5>" LOC = "D11" | IOSTANDARD = LVTTL | SLEW = SLOW | DRIVE = 4;
NET "led<6>" LOC = "E9"  | IOSTANDARD = LVTTL | SLEW = SLOW | DRIVE = 4;
NET "led<7>" LOC = "F9"  | IOSTANDARD = LVTTL | SLEW = SLOW | DRIVE = 4;
#
#
# Rotary encoder. 
#   Rotation contacts require pull UP resistors to provide High level.
#   Press contact requires pull DOWN resistor to provide Low when not pressed..
#
NET "rotary_a"     LOC = "K18" | IOSTANDARD = LVTTL | PULLUP;
NET "rotary_b"     LOC = "G18" | IOSTANDARD = LVTTL | PULLUP;
NET "rotary_press" LOC = "V16" | IOSTANDARD = LVTTL | PULLDOWN;
#
#
# End of File
#