10.4.1 Creating a RAM for IGLOO®, ProASIC® 3, SmartFusion® and Fusion

The core configurator automatically cascades RAM blocks to create wider and deeper memories by choosing the most efficient aspect ratio. It also handles the grounding of unused bits. The core configurator software supports the generation of memories that have different Read and Write aspect ratios.

You can create a Dual Port RAM or Two Port RAM core. A Dual Port RAM has read and write access on both ports while a Two Port RAM allows write access on one port and read access on the other port.

Each RAM topic has subtopics with additional information on I/O descriptions and parameters.

Related Topics

Caveats for RAM generation in the Libero IDE

Consider the following caveats when generating RAM in the Libero IDE:

  • If a word width of 9 is used for Read, then Write configurations of 1, 2 or 4 cause the MSB of the output to be undefined. These configurations are not supported.

  • The core configurator only supports depth and width RAM cascading up to 64 blocks.
  • The core configurator does not generate RAM based on a specific device. It is your responsibility to make sure the RAM fits physically on the device.
  • Dynamic configuration of the aspect ratios is supported only in the Fusion RAM with Initialization core.

  • The software returns a configuration error for unsupported configurations.

Tips

Use the following tips when generating RAM:
  • Writing different data to the same address using both ports in Dual Port RAM is undefined and should be avoided.
  • All unused inputs must be grounded.
  • WMODE is ignored during read operation.
  • RESET does not reset the memory contents. It resets only the output.
  • Writing to and reading from the same address is undefined and should be avoided. When using the RAM4K9 in Two Port mode, care should be taken that Read and Write operations are not going on simultaneously.