AD9162 boot loader pass bit low - reports engineering Revision

Hi all,

We follow the AD9162 DAC start-up sequence in Table 42, including setting up the SPI bus and configuring the NVRAM. Our board reports that the boot load pass bit (reg. 0x604 bit 1) is low. Upon looking into this I have noticed that the board reports unusual values for the product ID and revision.

We are using a custom dev board with our own driver software that is very similar to the AD916x driver. We can see it communicating just fine over SPI on the scope so I am confident that it not the SPI bus at fault. 

Our source code effectively looks like this:

write_reg(0x000, 0x18)

write_reg(0x0D2, 0x52)

write_reg(0x0D2, 0xD2)

write_reg(0x606, 0x02)

write_reg(0x607, 0x00)

write_reg(0x604, 0x01)

// sleep for 1000us

_chip_type = read_reg(0x003)

_chip_id = ((uint16_t) read_reg(0x004) << 0)  | ((uint16_t) read_reg(0x005) << 8)

uint8_t chip_grade_rev = read_reg(0x006)

_prod_grade = (chip_grade_rev >> 4)

_dev_revision = (chip_grade_rev & 0x0F)

Any guidance on what might be going wrong would be welcome.