DA6505.005

11 June 2018

17 (44)

for activating the EEPROM and EWE bits for

enabling the EEPROM for a write. See table 2. By

default the EEPROM is inactive (EON=000) and

write protected (EWE=00, EEPROM write disabled).

To read or write EEPROM it needs to be first

activated by setting EON=010 or 101. Any other

EON bit combination keeps the EEPROM inactive.

Note that to minimize current consumption the

EEPROM should be activated only during EEPROM

read or write operations and kept inactive in other

time. This is because an internal regulator is turned

on when the EEPROM is active. To read only the

EEPROM content the EEPROM control register

activating the EEPROM and before starting to read

or write the EEPROM there need to be a startup time

wait of least 0.2 ms. See also chapter EEPROM

READ ONLY PROCEDURE.

To write EEPROM it is necessary to additionally

enable the EEPROM for a write by setting EWE=01.

Alternatively EEPROM block write can be enabled by

setting EWE=10. However the block write is intended

only for testing purposes. Warning: The EEPROM

block write should not be used since the given

data

byte

overwrites

all

EEPROM

content

including the factory trimming values of the

oscillator

Any

other

EWE

bit

combination keeps the EEPROM write disabled.

This

write

protection

feature

is

for

avoiding

accidental overwrite of the EEPROM calibration

data. To both read and write EEPROM content the

EEPROM control register should be set to value

See

also

chapter

EEPROM

WRITE

PROCEDURE.

The

EEPROM

control

register

contains

also

EE_TEST bits which select different EEPROM test

modes. By default the EEPROM test mode is

disabled (EE_TEST=000).

The EE_TEST

bits

should be always kept at the default setting since

the other settings are only for EEPROM testing

purpose.

Bit Number

Bit Name

Description

Value

Function

7-5

EE_TEST

EEPROM test modes

000

001

010

011

100

101

110

111

EEPROM test mode disabled (default)

Charge pump verification, ETEST = VNEG

Charge pump verification, ETEST = VPOS

Oscillator verification, SDO = TCLK4M (Note 1)

Parallel endurance test

Read data retention test, NMART = 1 (Note 2)

Read data retention test, PMART = 1 (Note 3)

No test mode

4-3

EWE

Enable EEPROM write

00

01

10

11

EEPROM write disabled (default)

EEPROM normal write enabled

EEPROM block write enabled

EEPROM write disabled

2-0

EON

Activate EEPROM for

read or write

000

010

101

other

EEPROM inactive (default)

EEPROM activated

EEPROM activated

EEPROM inactive

Note 1. To get the EEPROM oscillator output TCLK4M from SDO pin, set the MSB bit ENTP = 1 in the Oscillator frequency

Note 2. VNEG margin voltage can be forced from ETEST pin

Note 3. VPOS margin voltage can be forced from ETEST pin