Hi! I'm trying to implement low power mode on lite5200b board (everything but sdram is powered off), and I seem to have problems with putting ram to self-refresh.
As far as I can tell I'm following datasheets, but if it sleeps for a day or so, contents of RAM get cleared to zeroes (I get 0x02800100 and similar patterns). Any ideas, tips, comments... anything really, is appreaciated. I'm also interested in mpc5200 "deep sleep", anyone had any success? Thanks! Domen Code for low power mode via "QT" chip. It is ran from flash, since sdram isn't accessible after this. // put sdram into self-refresh lis r5, 0xf000 ori r5, r5, 0x100 lwz r4, 0x4(r5) oris r4, r4, 0x8000 stw r4, 0x4(r5) // mode_en sync ori r4, r4, 0x0002 // setup soft_pre lis r6, 0xbfff ori r6, r6, 0xffff and r6, r4, r6 // setup !cke oris r6, r6, 0x1000 // setup ref_en stw r4, 0x4(r5) // soft_pre sync stw r6, 0x4(r5) // ref_en !cke sync clrlwi r6, r6, 1 // !mode_en stw r6, 0x4(r5) sync // turn off with QT chip lis r3, 0xf000 ori r3, r3, 0x0c00 li r4, 0x02 stb r4, 0(r3) // enable gpio_wkup1 sync stb r4, 8(r3) // output sync stb r4, 0xc(r3) // output high sync lis r5, 0x0001 delay_10us: addi r5, r5, -1 cmpi cr7, r5, 0 bne cr7, delay_10us sync // turn off li r4, 0 stb r4, 0xc(r3) // output low sync _______________________________________________ Linuxppc-embedded mailing list Linuxppc-embedded@ozlabs.org https://ozlabs.org/mailman/listinfo/linuxppc-embedded