A problem has been found with the post-MAP simulation of DSP48s when the C0 pin is either connected to GND or disconnected.
Case 1: C0 connected to GND
- Regardless of the state of the rest of the C bus pins, the CEC, RSTC and entire C bus is disconnected. [We expect the CEC, RSTC and C bus to be disconnected only if the *entire* C bus is connected to GND.]
Case 2: C0 is disconnected
- Regardless of the state of the rest of the C bus pins, the CEC and RSTC pins are disconnected. [We expect the CEC and RSTC pins to be disconnected only if the *entire* C bus is disconnected.]
This problem has been fixed in the latest 7.1i Service Pack available at:
The first service pack containing the fix is 7.1i Service Pack 2.
Meanwhile, a tactical patch is available.
To install, unzip in the XILINX install directory while maintaining directory structure.
tar zxvf 71isp1_par_lin_21018.tar.gz
gzip -d 71isp1_par_sol_21018.tar.gz
tar xvf 71isp1_par_sol_21018.tar