I find in the NS7520 Board,all the signal form CPU to SDRAM have a 33 resistor . Can I remove the resistor of SDRAM??
The Net+Arm provides internal SDRAM controller and that it generates BCLK signal, which clocks the SDRAM and local bus arbitration signals. In order to clock the PCI and/or CPLD would be to put a clock buffer on the BCLK that would put a propagation delay in the pico seconds only and then hook that the PCI and/or CPLD. Other wise hooking that directly could have side effects and here is the spec for such clock buffer… the enclosed CY2309 is what we use on the board. The 33 ohm resistors are needed based on the buffer so they are needed.