datasheetbank_Logo
Integrated circuits, Transistor, Semiconductors Search and Datasheet PDF Download Site

DS4412UR View Datasheet(PDF) - Maxim Integrated

Part Name
Description
View to exact match
DS4412UR Datasheet PDF : 0 Pages
Dual-Channel, I2C Adjustable
Sink/Source Current DAC
TYPICAL I2C WRITE TRANSACTION
MSB
START 1 0 0 1 0 0
LSB
MSB
LSB
MSB
LSB
0 R/W SLAVE b7 b6 b5 b4 b3 b2 b1 b0 SLAVE b7 b6 b5 b4 b3 b2 b1 b0 SLAVE STOP
ACK
ACK
ACK
SLAVE
READ/
REGISTER/MEMORY ADDRESS
DATA
ADDRESS
WRITE
EXAMPLE I2C TRANSACTIONS
A) SINGLE BYTE WRITE
-WRITE RESISTOR
F9h TO 00h
90h
F9h
START 1 0 0 1 0 0 0 0 SLAVE 1 1 1 1 1 0 0 1 SLAVE 0 0 0 0 0 0 0 0 SLAVE
ACK
ACK
ACK
STOP
90h
F8h
90h
DATA
B) SINGLE BYTE READ
-READ RESISTOR F8h
START
1 0010000
SLAVE
ACK
11111 000
SLAVE
ACK
REPEATED 1 0 0 1 0 0 0 1 SLAVE
START
ACK
Figure 2. I2C Communication Examples
MASTER
NACK
STOP
read sequence or as an indication that the device is
not receiving data.
Byte Write: A byte write consists of 8 bits of informa-
tion transferred from the master to the slave (most sig-
nificant bit first) plus a 1-bit acknowledgement from
the slave to the master. The 8 bits transmitted by the
master are done according to the bit-write definition,
and the acknowledgement is read using the bit-read
definition.
Byte Read: A byte read is an 8-bit information trans-
fer from the slave to the master plus a 1-bit ACK or
NACK from the master to the slave. The 8 bits of
information that are transferred (most significant bit
first) from the slave to the master are read by the
master using the bit read definition above, and the
master transmits an ACK using the bit write defini-
tion to receive additional data bytes. The master
must NACK the last byte read to terminated commu-
nication so the slave will return control of SDA to the
master.
Slave Address Byte: Each slave on the I2C bus
responds to a slave address byte sent immediately fol-
lowing a START condition. The slave address byte
contains the slave address in the most significant 7
bits and the R/W bit in the least significant bit. The
DS4412’s slave address is 90h.
When the R/W bit is 0 (such as in 90h), the master is
indicating it will write data to the slave. If R/W = 1
(91h in this case), the master is indicating it wants to
read from the slave. If an incorrect slave address is
written, the DS4412 assumes the master is commu-
nicating with another I2C device and ignores the
communication until the next START condition is
sent.
Memory Address: During an I2C write operation,
the master must transmit a memory address to iden-
tify the memory location where the slave is to store
the data. The memory address is always the second
byte transmitted during a write operation following
the slave address byte.
I2C Communication
Writing to a Slave: The master must generate a START
condition, write the slave address byte (R/W = 0), write
the memory address, write the byte of data, and gener-
ate a STOP condition. Remember that the master must
read the slave’s acknowledgement during all byte-write
operations.
Reading from a Slave: To read from the slave, the
master generates a START condition, writes the slave
address byte with R/W = 1, reads the data byte with a
NACK to indicate the end of the transfer, and generates
a STOP condition.
8 _______________________________________________________________________________________
 

Share Link: 

datasheetbank.com [ Privacy Policy ] [ Request Datasheet ] [ Contact Us ]