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[/] [leros/] [trunk/] [quartus/] [dspio/] [leros.sdc] - Rev 10
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###########################################################################
# SDC files for Cycore based boards
###########################################################################
# Clock in input pin (20 MHz)
create_clock -period 50.0 [get_ports clk]
# Create generated clocks based on PLLs
derive_pll_clocks
# ** Input/Output Delays
# -------------------
# MS: I want following constrains for the SRAM connection
# Input:
# maximum Tsu 2.2 ns
# maximum Tho ? ns (could be 0-2, will be negative anyway)
# Output:
# maximum Tco 3 ns
#
# Are the following constraints correct?
# I'm confused by the min/max input delay notion.
# Use FPGA-centric constraints (general pins)
# Tsu 5 ns
set_max_delay -from [all_inputs] -to [all_registers] 5
# the value is -th, so a negative hold time would be positive
set_min_delay -from [all_inputs] -to [all_registers] -0.0
# Tco 10 ns
set_max_delay -from [all_registers] -to [all_outputs] 10
# WTF shall this constraint be? A hold time on an output port?
set_min_delay -from [all_registers] -to [all_outputs] -0.0
# Use FPGA-centric constraints (SRAM pins)
# Tsu 2 ns
set_max_delay -from [get_ports *] -to [get_registers {*ram*}] 2.2
# Tco 3 ns
set_max_delay -from [get_registers *] -to [get_ports {ram*}] 3
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