> Well, we have some hardware where we can sleep everything but > memory and some where we can also leave the display active (and > backlit). In fact, however, today the latency for going to sleep > is too great to do so between frames, so we just do a wait there. [Woodruff, Richard] In effect OMAP2/3 can auto idle to low power states in between LCD FIFO refills. The SDRAM, the DPLL and interconnects can be auto-idled between LCD FIFO loads. By carefully setting your LCD FIFO thresholds you can spin back up the DPLL, memory and interconnect in time to load up the LCD FIFO, then back to sleep. Its not just LCD, other devices can do the same. Say pushing data into an audio codec's FIFO. Getting this effect does require device coordination. If a device objects you don't hit the big savings. Regards, Richard W.
