Hi NXP friends,
Here i have a question about i.MX6Q boot from SD2, the BOOT_CFG1 and BOOT_CFG2 are configured to boot from SD2, a 4 bit TF card in my customerized board, below is the schematic detail.
i configured BOOT_MODE[1:0] to 1:0, for the Internal Boot.
1. the boot config resistor:
the green marked resistor is removed;
2. the SD2 interface:
in this condition the BOOT_CFG1 and BOOT_CFG2 are configured as below.
all the power supply domain works fine, i checked one by one by Oscilloscope, it meet the power up sequence very well, as i expected, once i power up the board, CPU will boot from SD2, and i should see the SD2_CLK in scope, but there is no waveform at all.
i guess the BOOT_CFG1 and BOOT_CFG2 configuration IO voltage might be in wrong level, so i checked EIM _DA6 and EIM_DA14 voltage during power up, it seems the voltage is low, can not be pulled up by the reisistor.
it means the all BOOT_CFG1 and BOOT_CFG2 are 0, that's why it can not boot from SD2.
i also check these 2 pins, it seems that they are output during power up, is it NorFlash interface boot here?
i searched in internet, and somebody told it's about fuse, i also checked the fuse initial value of BT_FUSE_SEL is 0 as described in i.MX6 reference manual 3.8.1.
the BOOT_MODE is 1:0, and BT_FUSE_SEL is 0, so CPU should boot from SD2 by GPIO pins configuration.
if i use MFGtool download from USB, it works fine in downloading, but it can not boot from SD2 at all, it seems CPU doesn't check SD2 while booting, no SD2_CLK output, and EIM _DA6 and EIM_DA14 are all low in voltage.
need your suggestion on that.
thanks in advance.