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| author | Ian Buckley <ianb@server2.ionconcepts.com> | 2010-09-30 15:54:03 -0700 |
|---|---|---|
| committer | Ian Buckley <ianb@server2.ionconcepts.com> | 2010-09-30 15:54:03 -0700 |
| commit | 1c3dfe21f8bacbf762b440a23ce652a879288615 (patch) | |
| tree | de38fdff2848091a8c2c0ac1ab201a679c5e14d6 | |
| parent | 7ffe28ccc6059ae3caa500e35b76718ae6ff100a (diff) | |
| download | uhd-1c3dfe21f8bacbf762b440a23ce652a879288615.tar.gz uhd-1c3dfe21f8bacbf762b440a23ce652a879288615.tar.bz2 uhd-1c3dfe21f8bacbf762b440a23ce652a879288615.zip | |
Modified phase shift of DCM1 to -64 which is intended to give more timing margin on reads from the SRAM at the expense of Writes to the SRAM.
Tested to be at least as stable as a phase shift of 12 and beter looking timing on the logic analyzer.
Signals driven by the FPGA are observed changing on the SRAM pins about 4 nS after the rising edge of the RAM clock.
| -rw-r--r-- | usrp2/top/u2_rev3/u2_rev3.v | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/usrp2/top/u2_rev3/u2_rev3.v b/usrp2/top/u2_rev3/u2_rev3.v index 079a5cc4c..53f1e0a14 100644 --- a/usrp2/top/u2_rev3/u2_rev3.v +++ b/usrp2/top/u2_rev3/u2_rev3.v @@ -409,7 +409,7 @@ module u2_rev3 defparam DCM_INST1.DLL_FREQUENCY_MODE = "LOW"; defparam DCM_INST1.DUTY_CYCLE_CORRECTION = "TRUE"; defparam DCM_INST1.FACTORY_JF = 16'h8080; - defparam DCM_INST1.PHASE_SHIFT = -12; + defparam DCM_INST1.PHASE_SHIFT = -64; defparam DCM_INST1.STARTUP_WAIT = "FALSE"; IBUFG RAM_CLK_buf_i1 (.I(RAM_CLK), |