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Altera_Forum
Honored Contributor
16 years agoI have the same trouble.
I'm using a DK-DSP-3C120N kit.Recently,I'm struggling with the DDR2 HP Controller under the direction of AN517(Using High-Performance DDR, DDR2, and DDR3 SDRAM With SOPC Builder).The design is targeted to the Cyclone® III EP3C120F780C7 Kit. In this example,the SOPC system contain a Half-Rate DDR2 Controller working at 150MHz(altmemddr_auxfull),the PLL of the controller simultaneously generate a 75MHz output clock(altmemddr_sysclk) which been used as SOPC system clock. After compilation,I got three critical warning,cause by JTAG.The TimeQuest report negative slack(-2.435) in Summary(Removal) of altera_reserved_tck. The Top Failing Paths (Removal:altera_reserved_tck) is this: Slack:-2.435 From---altera_reserved_tck To-----pzdyqx:nabboc|pzdyqx_impl:zdyqx_impl_inst|FNUJ6967 I've tried to slow the DDR2 clock down to 133.333MHz,the NIOS clock down to 66.667MHz,but the slack value still negative. I lose my head of this because I've constrained the JTAG using the templet:# JTAG Signal Constraints constrain the TCK port create_clock -name tck -period 100.000 [get_ports altera_reserved_tck]# Cut all paths to and from tck set_clock_groups -asynchronous -group [get_clocks altera_reserved_tck]# Constrain the TDI port set_input_delay -clock altera_reserved_tck -clock_fall 1 [get_ports altera_reserved_tdi]# Constrain the TMS port set_input_delay -clock altera_reserved_tck -clock_fall 1 [get_ports altera_reserved_tms]# Constrain the TDO port set_output_delay -clock altera_reserved_tck -clock_fall 1 [get_ports altera_reserved_tdo] Can anybody help us? Thank you very much!