cat5411 Catalyst Semiconductor, cat5411 Datasheet - Page 8

• Manufacturer Part Number: cat5411
• Description: Dual Digitally Programmable Potentiometers Dpp? With 64 Taps And Spi Interface
• Manufacturer: Catalyst Semiconductor

CAT5411
INSTRUCTION AND REGISTER
DESCRIPTION
DEVICE TYPE / ADDRESS BYTE
The first byte sent to the CAT5411 from the master/
processor is called the Device Address Byte. The
most significant four bits of the Device Type address
are a device type identifier. These bits for the
CAT5411 are fixed at 0101[B] (refer to Table 1).
The two least significant bits in the slave address
byte, A1 - A0, are the internal slave address and must
match the physical device address which is defined by
the state of the A1 - A0 input pins for the CAT5411 to
successfully continue the command sequence. Only
the device which slave address matches the incoming
device address sent by the master executes the
instruction. The A1 - A0 inputs can be actively driven
by CMOS input signals or tied to V
remaining two bits in the device address byte must be
set to 0.
Table 1. Identification Byte Format 0 1 0 Device Type Identifier (MSB)
Table 2. Instruction Byte Format
Figure 3. Potentiometer Timing (for All Load Instructions)
Doc. No. MD-2114 Rev. I
V
W
SCK
/R
SO
CS
SI
W
(MSB)
High Impedance
I3
(MSB)
ID3
0
M
S
I2
B
ID2
Instruction
1
Opcode
Device Type
Identifier
I1
CC
ID1
0
or V
SS
. The
I0
ID0
1
8
R1
INSTRUCTION BYTE
The next byte sent to the CAT5411 contains the
instruction and register pointer information. The four
most significant bits used provide the instruction
opcode I [3:0]. The R1 and R0 bits point to one of the
four data registers of each associated potentiometer.
The least two significant bits point to one of two Wiper
Control Registers. The format is shown in Table 2.
Data Register Selection
Data Register
0
Selection
• • •
• • •
Data Register Selected
R0
0
Slave Address
t
WRL
DR0
DR1
DR2
DR3
L
S
WCR/Pot Selection
P1
B
A1
Characteristics subject to change without notice
(LSB)
P0
(LSB)
A0
© Catalyst Semiconductor, Inc.
R1
0
0
1
1
R0
0
1
0
1