TimeQuest做时序分析时遇到hold违约,求教如何解决?
时间:10-02
整理:3721RD
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rt,小弟最近在用altera做一个fpga的工程。需要用到两个串联的时钟复用器,如下图所示:
clk_out最后是给了altera自带双口ram的写时钟断。在做apr后的时序分析时,有警告:Critical Warning: Timing requirements not met 仔细看了报告里的描述,应该是hold的时序违约。我用的是TimeQuest做的,sdc如下:
###########################################################################
#
# Generated by : Version 9.1 Build 222 10/21/2009 SJ Full Version
#
# Project : spi_80
# Revision : spi_80
#
# Date : Thu Nov 20 10:16:34 CST 2014
#
###########################################################################
# WARNING: Expected ENABLE_CLOCK_LATENCY to be set to 'ON', but it is set to 'OFF'
# In SDC, create_generated_clock auto-generates clock latency
#
# ------------------------------------------
#
# Create generated clocks based on PLLs
derive_pll_clocks -use_tan_name
#
# ------------------------------------------
# Original Clock Setting Name: WRB
create_clock -period 200 -name {WRB_SCL_i} {WRB_SCL_i}
# ---------------------------------------------
# Original Clock Setting Name: SCK
create_clock -period 200 -name {SCK_i} {SCK_i}
# ---------------------------------------------
# Original Clock Setting Name: rCLK_ram
create_clock -period 200 -name rCLK_ram [get_ports {gram_rck}]
# ---------------------------------------------
create_clock -period 100 -name dotclk [get_ports {dotclk}]
# ** Clock Latency
# -------------
# ** Clock Uncertainty
# -----------------
# ** Multicycles
# -----------
# ** Cuts
# ----
# ** Input/Output Delays
# -------------------
# ** Tpd requirements
# ----------------
# ** Setup/Hold Relationships
# ------------------------
# ** Tsu/Th requirements
# -------------------
# ** Tco/MinTco requirements
# -----------------------
#
# Entity Specific Timing Assignments found in
# the Timing Analyzer Settings report panel
#
# ---------------------------------------------
# The following clock group is added to try to
# match the behavior of:
# CUT_OFF_PATHS_BETWEEN_CLOCK_DOMAINS = ON
# ---------------------------------------------
set_clock_groups -exclusive -group {SCK_i} -group {WRB_SCL_i} -group {rCLK_ram} -group {dotclk}
# ---------------------------------------------
请问大神们如何能解决这个hold违约啊?貌似跟时钟周期没有关系啊。新手求指导!非常感谢!
同样菜鸟一个 求大神解答
顶一下,还是没有解决。现在重新改下代码再试下
问题解决了:assignments-setting-filter-Settings-optimize hold timing 选择all path
感谢csdn的net_xurong:http://blog.csdn.net/net_xurong/article/details/4885756
