MAX5419 Maxim Integrated Products, MAX5419 Datasheet - Page 11

• Manufacturer Part Number: MAX5419
• Description: 256-Tap Nonvolatile I2C-Interface Digital Potentiometers
• Manufacturer: Maxim Integrated Products

A write to the MAX5417/MAX5418/MAX5419 consists of
the transmission of the device’s slave address with the
8th bit set to zero, followed by at least 1 byte of infor-
mation (Figure 7). The 1st byte of information is the
command byte. The bytes received after the command
byte are the data bytes. The 1st data byte goes into the
internal register of the MAX5417/MAX5418/MAX5419 as
selected by the command byte (Figure 8).
Use the command byte to select the source and desti-
nation of the wiper data (nonvolatile or volatile memory
registers) and swap data between nonvolatile and
volatile memory registers (see Table 2).
Figure 7. Command Byte Received
Figure 8. Command and Single Data Byte Received
S
HOW CONTROL BYTE AND DATA BYTE MAP INTO
S
MAX5417/MAX5418/MAX5419 REGISTERS
SLAVE ADDRESS
CONTROL BYTE IS STORED ON RECEIPT OF STOP CONDITION
MAX5417/MAX5418/MAX5419
______________________________________________________________________________________
Message Format for Writing
ACKNOWLEDGE FROM
SLAVE ADDRESS
NOP/W
256-Tap, Nonvolatile, I
MAX5417/MAX5418/MAX5419
0
ACKNOWLEDGE FROM
A
Command Byte
NOP/W
D15 D14 D13 D12 D11 D10
0
MAX5417/MAX5418/MAX5419
CONTROL BYTE
A
ACKNOWLEDGE FROM
D15
VREG: The data byte writes to the volatile memory reg-
ister and the wiper position updates with the data in the
volatile memory register.
NVREG: The data byte writes to the nonvolatile memo-
ry register. The wiper position is unchanged.
NVREGxVREG: Data transfers from the nonvolatile
memory register to the volatile memory register (wiper
position updates).
VREGxNVREG: Data transfers from the volatile memo-
ry register into the nonvolatile memory register.
Digital Potentiometers
D14
D9
D13
D8
CONTROL BYTE
D12
A
D7
MAX5417/MAX5418/MAX5419
D11
D6
ACKNOWLEDGE FROM
D10
D5
MAX5417/MAX5418/MAX5419
2
C-Interface,
DATA BYTE
D9
D4
1 BYTE
ACKNOWLEDGE FROM
Command Descriptions
D3
D8
w
D2
A
D1
w
P
D0
A
w
P
11
.
D