Note: To specify the port widths using the dual-port mode of the block RAM, designers must use the
READ_WIDTH_[A|B] and WRITE_WIDTH_[A|B] attributes.
These rules should be considered:
- Designing a single-port block RAM requires the port pair widths of one write and one read to be set (for example, READ_WIDTH_A and WRITE_WIDTH_A).
- Designing a dual-port block RAM requires all port widths to be set.
- In simple dual-port mode, one side of the ports is fixed while the other side can have a variable width. The RAMB18E5 has a data port width of up to 36, while the RAMB36E5 has a data port width of up to 72. When using the block RAM as read-only memory, only the READ_WIDTH_A/B is used.