PT保持时间违例，removal违例，min_capacitance违例，求解决办法
将时钟保持时间的不确定性改为0.5，则保持时间违例修正，removal 数减少；输入驱动单元buffer已是最小的最大输出电容负载，求修正min_capacitance方式
最初始的违例部分报告如下：
****************************************
Report : constraint
-all_violators
-path slack_only
Design : SPI_S
Version: D-2010.06-SP3
Date: Wed Jan 27 21:35:32 2016
****************************************
min_delay/hold ('clk_in' group)
EndpointSlack
-----------------------------------------------------------------
ACR[7]-1.17(VIOLATED)
SSYNC-1.17(VIOLATED)
ODAC[7]-1.17(VIOLATED)
misoe-1.17(VIOLATED)
RESET-1.16(VIOLATED)
DRDY_f-1.14(VIOLATED)
uut_spi_slave/r_dorc_reg/D-1.13(VIOLATED)
misoo-1.12(VIOLATED)
uut_spi_slave/uut_reset_DRDY/reset_DRDY_reg/D-1.12(VIOLATED)
uut_spi_slave/reset_order_reg/D-1.11(VIOLATED)
uut_spi_slave/MODU_reg[0]/D-1.11(VIOLATED)
uut_spi_slave/MODU_reg[1]/D-1.11(VIOLATED)
uut_spi_slave/MODU_reg[4]/D-1.11(VIOLATED)
uut_spi_slave/MODU_reg[5]/D-1.11(VIOLATED)
uut_spi_slave/MODU_reg[6]/D-1.11(VIOLATED)
uut_spi_slave/SETUP_reg[2]/D-1.11(VIOLATED)
uut_spi_slave/SETUP_reg[3]/D-1.11(VIOLATED)
uut_spi_slave/uut_reset_DRDY/DRDY_state_reg[2]/D-1.11(VIOLATED)
-----------------------------------------------------------------
removal
EndpointSlack
-----------------------------------------------------------------
uut_Reset_Synchronizer/rff1_reg/CDN-2.02(VIOLATED)
uut_Reset_Synchronizer/rst_n_reg/CDN-2.02(VIOLATED)
uut_sync_detect/SYNC_r1_reg/CDN-1.63(VIOLATED)
uut_sync_detect/SYNC_r2_reg/CDN-1.63(VIOLATED)
uut_spi_slave/MODU_reg[0]/CDN-1.63(VIOLATED)
uut_spi_slave/MODU_reg[1]/CDN-1.36(VIOLATED)
uut_spi_slave/MODU_reg[2]/CDN-1.36(VIOLATED)
uut_spi_slave/MODU_reg[3]/CDN-1.36(VIOLATED)
uut_spi_slave/DRDY_f_reg/CDN-1.33(VIOLATED)
-----------------------------------------------------------------
min_capacitance
RequiredActual
PinCapacitanceCapacitanceSlack
-----------------------------------------------------------------
uut_spi_slave/U259/Z0.020.010.00(VIOLATED: increase significant digits)
uut_spi_slave/U262/Z0.020.010.00(VIOLATED: increase significant digits)
uut_spi_slave/U284/Z0.020.010.00(VIOLATED: increase significant digits)
uut_spi_slave/U305/Z0.020.010.00(VIOLATED: increase significant digits)
uut_spi_slave/U313/Z0.020.010.00(VIOLATED: increase significant digits)
uut_spi_slave/U321/Z0.020.010.00(VIOLATED: increase significant digits)
-----------------------------------------------------------------
hold和removal可以垫buffer垫掉，不过你这violation太大了，估计要垫好多buffer。min_capacitance可以size up这些Z端的cell
我把时钟不确定性改小了，保持时间违例便修正了。removal通过插buffer，改器件大小已修正。现还有min_capacitance违例，最大负松弛为-0.0350035,最小负松弛-0.0000682799。想问一下：PT工具手动插入buffer后，如何删除?用指令老是错误。有没有PT软件的使用教程啊?想改错，电路图中好难找到cell