Hello, I built a board really similar to beagleboard rev4 from scratch. I just added some USB ports and other few changes.(buy the components, manufacture it, design the layers..etc) After some problems I finally got a “40W” in the terminal connected to UART3. I could not boot from SDCard because, despite the voltage in VMMC1 is 3V, my WP, DAT[3-0] and CMD pins have a strange voltage value. The voltage values measured in the SDCard reader are shown in this table:
MY BEAGLE ORIGINAL BEAGLE 0.5 V 1.8 V WP Conected to OMAP 1.8 V 1.8 V CD Conected to TPS65950 0.51 V 3 V DAT1 Conected to OMAP 0.507 V 3 V DAT0 Conected to OMAP 0 V 0.078 V DAT7 Conected to OMAP Powered by VSIM 0 V 0 V GND 0 V 0.072 V DAT6 Conected to OMAP Powered by VSIM CLK Conected to OMAP 3 V 3 V VDD 0 V 0 V GND 0 V 0.072 V DAT5 Conected to OMAP Powered by VSIM 0.5 V 3 V CMD Conected to OMAP 0 V 0.073 V DAT4 Conected to OMAP Powered by VSIM 0.513 V 3 V DAT3 Conected to OMAP 0.507 V 3 V DAT2 Conected to OMAP After check the voltages in a real beagleboard I found that DAT[0-3] and CMD are 3V. I have been searching a lot but I could not find why my voltage values are wrong. The hardware configuration is the same as the original beagleboard: to power OMAP3530 I am using TPS65950. The only difference is that due to a design fail I needed to cut the connection of VMMC1 with the TPS65950 and I am powering VMMC1 with an external source (3V). I took care of give power to VDD in the card reader and to VDDS_MMC1 in the OMAP3530. VSIM is 0V after reset despite VAUX12S is powered at 3.6V. I could not load any loader into the board yet. If I can not fix MMC problems I will try to boot from UART, because of the 40W it seems that the OMAP processor is alive. Really thanks. PD: 1) Because all the wrong voltages in my board are almost the same value (0.5 V) I thought that maybe the original beagleboards comes with a different preconfigured pins state-after-reset (pull-down or something) than the OMAP3530 bought directly??? 2) Can I say that VMMC1 is reaching correctly the VDDS_MMC1 pin in the OMAP3530 because of the 0.5V in the pins? or the connection between VMMC1 and VDDS_MMC1 could be cut despite the 0.5V? -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to beagleboard+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
