[已解决]TimeQuest做时序分析时遇到hold违约，求教如何解决？

dennisi123

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！

向阳天up

同样菜鸟一个 求大神解答

dennisi123

顶一下，还是没有解决。现在重新改下代码再试下

dennisi123

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