24LC32A-MT MicrochipTechnology, 24LC32A-MT Datasheet - Page 6

• Manufacturer Part Number: 24LC32A-MT
• Description: 32KI2CSerialEEPROMinISOMicromodule
• Manufacturer: MicrochipTechnology

24LC32A MODULE
5.0
A control byte is the first byte received following the
start condition from the master device. (See Figure 5-
1) The control byte consists of a four bit control code;
for the 24LC32A this is set as 1010 binary for read and
write operations. The next three bits are device select
bits on standard devices, however, for micromodules,
these must be zeros. The last bit of the control byte
defines the operation to be performed. When set to a
one a read operation is selected, and when set to a
zero a write operation is selected. The next two bytes
FIGURE 5-1:
FIGURE 5-2:
DS21225A-page 6
Start Bit
S
1
DEVICE ADDRESSING
1
Address
Slave
0
Control Code
CONTROL BYTE
0
1
CONTROL BYTE FORMAT
ADDRESS SEQUENCE BIT ASSIGNMENTS
Slave Address
0
1
0
Device
Select
0
Bus
0
Read/Write Bit
Device Select
0
Acknowledge Bit
0
Bits
R/W
0
0
R/W
0
ACK
0
ADDRESS BYTE 1
0
0
11
A
received define the address of the first data byte (see
Figure 5-2). Because only A11...A0 are used, the
upper four address bits must be zeros. The most signif-
icant bit of the most significant byte of the address is
transferred first.
Following the start condition, the 24LC32A monitors
the SDA bus checking the device type identifier being
transmitted. Upon receiving a valid control byte, the
slave device outputs an acknowledge signal on the
SDA line. Depending on the state of the R/W bit, the
24LC32A will select a read or write operation
10
A
A
9
A
8
A
7
ADDRESS BYTE 0
1997 Microchip Technology Inc.
A
0