Hi,
we would like to use XINTF for connecting a TMS320C28346 TI Delfino control card to an ADC having a parallel interface. The problem is that the ADC requires CS to be low for quite some time (200 ns). The XINTF at most can keep CS low for 6 (lead time) + 14 (active time) + 6 (trail time) = 26 tc(XTIM). If we use the processor at maximum speed, i.e., 300 MHz, then tc(XTIM) = 6.66 ns, therefore 200 ns cannot be reached with 26 clock cycles (26*6.66 = 173 ns).Interestly we only have to write to the ADC at the beginning and never again.
We came up with some solutions:
1) Reduce the clock speed of the processor. But we do not like to loose performance. Is it possible to reprogram the PLL "on-the-fly" to increase the processor speed after the ADC has been configured?
2) Write our own driver for writing and use XINTF for reading. Question. Is this solution feasible? Is it possible to reprogram the GPIO's as XINTF pins "on-the-fly"?
3) Use somehow the Xready signal but the ADC does not provide this output, therefore we should generate it with either a PWM or with a GPIO (with some interrupt). Do you think this will work?
Any other solution?
Best