Hello,
The RAMB16 component has much less clock-to-out time when using the optional output register. However, I need valid data one clock cycle after the address input is valid.
The Virtex-4 User Guide ug070 states in Figure 4-5 (Page 115) that there are two optional inverters in the clock path. Also the port signal description (pg. 119): CLK polarity is configurable.
I wanted to enable both inverters. The RAM content should than be clocked out at the falling edge. And the register delivers data at the following rising edge.
Problem: There are only generic parameters to enable the clock inverter at the output register: INVERT_CLK_DO[A|B]_REG
Does anyone know how I can adjust the clock polarity (without using the DCM CLK180 output)?
Thanks
Frank