The DACx3701 contain nonvolatile memory (NVM) bits. These memory bits are user programmable and erasable, and retain the set values in the absence of a power supply. All the register bits, as shown in Table 8-2, can be stored in the device NVM by setting NVM_PROG = 1 (address D3h). The NVM_BUSY bit (address D0h) is set to 1 by device when a NVM write or reload operation is ongoing. During this time, the device blocks all write operations to the device. The NVM_BUSY bit is set to 0 after the write or reload operation is complete; at this point, all write operations to the device are allowed. The default value for all the registers in the DACx3701 is loaded from NVM as soon as a POR event is issued. Do not perform a read operation from the DAC register while NVM_BUSY = 1.

The DACx3701 also implement NVM_RELOAD bit (address D3h). Set this bit to 1 for the device to start an NVM reload operation. After the operation is complete, the device autoresets this bit to 0. During the NVM_RELOAD operation, the NVM_BUSY bit is set to 1.