AR #33019 - Spartan-6 Clocking - DCM_CLKGEN Spread Spectrum Clock Generation feature support
Spartan-6 Clocking - DCM_CLKGEN Spread Spectrum Clock Generation feature support
| AR# | 33019 |
| Part | FPGA-Spartan-Clock Manager |
| Last Modified | 2009-06-23 00:00:00.0 |
| Status | Active |
| Keywords | generation, DCM_CLKGEN |
Description
Keywords: generation, DCM_CLKGEN
This Answer Record outlines the support for the DCM_CLKGEN feature on the Spartan-6 device and in the ISE software tools.
Solution
In the Spartan-6 devices, the DCM_CLKGEN primitive is able to create a spread spectrum clock. This feature is used by setting the SPREAD_SPECTRUM attribute, which can be accessed with in the 11.2 software. However, there is an incomplete solution in ISE 11.2 and Spread Spectrum is NOT supported in ISE 11.2. Spread Spectrum will NOT work on the device with a bitstream generated in ISE 11.2. There is no way to use the Spread Spectrum clocking with the ISE 11.2 software.The next version of software will fully support the Spread Spectrum feature of DCM_CLKGEN. Along with software support, there will be additional documentation, reference material, and reference designs. This Answer Record will be updated with that information when it becomes available.