Datasheet
EEPROM is short for Electrically Erasable
Programmable Read Only Memory. It is usually
a secondary storage memory in devices containing
data that is retained even if the device looses power
supply. Because of the ability to alter single bytes
of data, EEPROM devices are used to store personal
preference and conguration data in a wide spectrum
of consumer, automotive, telecommunication, medical,
industrial, and PC applications.
EasyMx PRO
™
v7 for STM32 supports serial EEPROM which
uses I
2
C communication interface and has 1024 bytes of
available memory. EEPROM itself supports single byte or 16-byte
(page) write and read operations. Data rates are dependent of power
supply voltage, and go up to 400 kHz for 3.3V power supply.
other modules
page 37
I
2
C EEPROM
In order to connect I
2
C EEPROM to the
microcontroller you must enable SW14.1 and
SW14.2 switches, as shown on Figure 23-2. 2K2
pull-up resistors necessary for I
2
C communication
are already provided on SDA and SCL lines once
switches are turned on. Prior to using EEPROM
in your application, make sure to disconnect
other peripherals, LEDs and additional pull-up
or pull-down resistors from the PB6 and PB7
communication lines that could interfere with the
data signals and cause data corruption.
I
2
C is a multi-master serial single-ended bus that is used to attach low-speed peripherals to computer or embedded
systems. I²C uses only two open-drain lines, Serial Data Line (SDA) and Serial Clock (SCL), pulled up with
resistors. SCL line is driven by a master, while SDA is used as bidirectional line either by master or slave device.
Up to 112 slave devices can be connected to the same bus. Each slave must have a unique address.
Enabling I
2
C EEPROM
What is I
2
C?
Figure
23-2: Turn
on switches
SW14.1
and SW14.2
to connect
EEPROM lines
to MCU
Figure 23-1:
Schematic of
I
2
C EEPROM
module
EasyMx PRO
v7
C36
100nF
1
2
3
54
6
7
8
A0
A1
A2
VSS SDA
SCL
WP
VCC
U9
24AA01 EEPROM
VCC-3.3VVCC-3.3V
VCC-3.3V
R72
2K2
R73
2K2
VCC-3.3V
EEPROM-SCL
EEPROM-SDA
EEPROM-SDA
EEPROM-SCL
1 2
3 4 5 6 7 8
O
N
SW14
PB6
PB7
DATA BUS