Maximum speed of data transfer from external RAM for LPC2292/2294
2005-03-02 by kbshah_2000
Please let me know if any one has tried to measure maximum data transfer rate from external memory (using CS2 --i.e. RAM at location selected by CS2 ) and another RAM/device at location CS3. I could not attain higher speed. My aim is to use PWM to generate clock @2MHz speed and want to attain data transfer for each clock from external ADC to External RAM. My PLL is eanbled and it runs CPU at 60Mhz. VPB divider is set to 2 to provide bus clock of 30Mhz. PWM match0 is 15 PWM match3 is 8. PWM match 4 is 0 and I am using double edge mode. I need transfer for every clock (I have tried with and without interrupt i.e. polling mode but coulsd not get data transfer at the same rate (I have look at the CS2 nd CS2 signal with respect to PWM output andmeasured the frequency. PWM output is at correct frequency. I am running my code from internal RAM ..IAR 4.20A is used and I have tried optimization for speed and without optimization modes... Any suggestion ...??? What could be wrong or missing k b shah