The DS320PR1601 can also be configured by reading from EEPROM. To enter into this mode MODE pin must be set to L1. The EEPROM load operation only happens once after the device's initial power-up. If the DS320PR1601 is configured for SMBus controller mode, then it will remain in the SMBus IDLE state until the READ_EN_N pin is asserted to LOW. After the READ_EN_N pin is driven LOW, the DS320PR1601 becomes an SMBus controller and attempts to self-configure by reading device settings stored in an external EEPROM (SMBus 8-bit address 0xA0). When the DS320PR1601 has finished reading from the EEPROM successfully, it will drive the ALL_DONE_N pin LOW. SMBus/I²C target operation is available in this mode before, during or after EEPROM reading. Note during EEPROM reading if the external SMBus/I²C controller wants to access DS320PR1601 registers it must support arbitration.

When designing a system for using the external EEPROM, the user must follow these specific guidelines:

• EEPROM size of 2Kb (256 × 8-bit) is recommended.
• Set MODE = L1, configure for SMBus controller mode
• The external EEPROM device address byte must be 0xA0 and capable of 400 kHz operation at 3.3 V supply
• In SMBus/I²C modes the SCL, SDA pins must be pulled up to a 3.3 V supply with a pull-up resistor. The value of the resistor depends on total bus capacitance. 4.7 kΩ is a good first approximation for a bus capacitance of 10 pF.

Refer to the DS160PR1601 and DS320PR1601 Programming Guide for detail register sets and control configuration procedures.