#171: AT24C32 IC (LCD Storage Chip; EEPROM Memory)

R4.12

The Turbo IC 24C32 is a serial 32K EEPROM fabricated
with Turbo’s proprietary, high reliability, high performance
CMOS technology. It’s 32K of memory is organized as 4,096
x 8 bits. The memory is configured as 256 pages with each
page containing 32 bytes. This device offers significant advantages
in low power and low voltage applications.
The Turbo IC 24C32 uses the extended I²C addressing protocol
and 2-wire serial interface which includes a bidirectional
serial data bus synchronized by a clock. It offers a
flexible byte write and a faster 32-byte page write. The data
in the upper quadrant of memory can be protected by a write
protect pin.
The Turbo IC 24C32 is assembled in either a 8-pin PDIP or
8-pin SOIC package. Pin #1 (A0), #2 (A1), and #3 (A2) are
device address input pins which are hardwired by the user.
Pin #4 is the ground (Vss). Pin #5 is the serial data (SDA)
pin used for bidirectional transfer of data. Pin #6 is the serial
clock (SCL) input pin. Pin #7 is the write protect (WP) input
pin, and Pin #8 is the power supply (Vcc) pin.
All data is serially transmitted in bytes (8 bits) on the SDA
bus. To access the Turbo IC 24C32 (slave) for a read or write
operation, the controller (master) issues a start condition by
pulling SDA from high to low while SCL is high. The master
then issues the device address byte which consists of 1010
(A2) (A1) (A0) (R/W). The 4 most significant bits (1010) are a
device type code signifying an EEPROM device. The A[2:0]
bits represent the input levels on the 3 device address input
pins. The read/write bit determines whether to do a read or
write operation. After each byte is transmitted, the receiver
has to provide an acknowledge by pulling the SDA bus low
on the ninth clock cycle. The acknowledge is a handshake
signal to the transmitter indicating a successful data transmission.