CDB5467U

DS714DB1

7

1.6

Auto-boot Mode

With a jumper connection on J18 (AUTO-BOOT ENABLE), the CS5467 operates in auto-boot mode and

the CDB5467U board operates as a stand-alone system without attaching it up to a PC. When in auto-

boot mode, a hardware reset (press on S1) will cause the CS5467 to boot up using the serial data from

the serial EEPROM on the board (U10). When the CS5467 is in auto-boot mode, the SPI connections

between the microcontroller and the CS5467 are removed and the GUI software can not access the

CS5467 registers and functions.

The EEPROM must be programmed prior to the auto-boot sequence. When the CDB5467U Evaluation

Board is sent from the factory, the EEPROM is programmed with the following CS5467 command/data

sequence:

1.

0x7E 0x00 0x00 0x01

2. Write Modes register, turn high-pass filters on:

0x60 0x00 0x01 0xE0

3.

0x7E 0x00 0x00 0x00

4. Set bit 2 (LSD) in the Mask register:

0x74 0x00 0x00 0x04

5. Start continuous conversion:

0xE8

6. Write STOP bit in Control register, to terminate auto-boot sequence:

0x78 0x00 0x01 0x00

This sequence programs the CS5467 for continuous conversion mode. If voltage and current signals are

applied to the inputs, the CS5467 will issue pulses on the E1 pin. See the CS5467 data sheet for more

details on auto-boot.