User`s guide

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 conguration data in a wide spectrum
of consumer, automotive, telecommunication, medical,
industrial, and PC applications.
EasyPIC
™
v7 supports serial EEPROM which uses I
2
C
communication interface and has 1024 bytes of available
memory. Board contains socket for serial EEPROMs in DIP8
packaging, so you can easily exchange it with dierent memory
size EEPROM IC. EEPROM itself supports single byte or 16-byte (page)
write and read operations. Data rate is 400 kHz for both 3.3V and 5V
power supply.
In order to connect I
2
C EEPROM to the
microcontroller you must enable SW4.7 and
SW4.8 switches, as shown on Figure 18-1. 1kΩ
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 interface lines in order
not to interfere with signal/data integrity.
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.
I
2
C EEPROM
C24
100nF
R4
1K
R5
1K
EEPROM-SCL
EEPROM-SDA
1 2 3 4 5 6 7 8
O
N
SW4
A0
A1
A2
VSSSDA
SCL
WP
VCC
1
2
3
45
6
7
8
U8
24C08
EEPROM-SCL
EEPROM-SDA
RC3
RC4
VCC-MCU VCC-MCU VCC-MCU
DATA BUS
Enabling I
2
C EEPROM
What is I
2
C?
Figure 18-1:
Activate SW4.7 and
SW4.8 switches
to connect
microcontroller
I
2
C lines to Serial
EEPROM.
page 31
Figure 18-1:
Schematic of
I
2
C EEPROM
module
modules