ISL23415 Datasheet, PDF (14/19 Pages) Intersil Corporation – Single, Low Voltage Digitally Controlled Potentiometer (XDCP™)

ISL23415
Write Operation
A write operation to the ISL23415 is a two or more bytes
operation. It requires first, the CS transition from HIGH-to-LOW.
Then host send a valid Instruction Byte, followed by one or more
Data Bytes to SDI pin. The host terminates the write operation by
pulling the CS pin from LOW-to-HIGH. Instruction is executed on
rising edge of CS.
Read Operation
A Read operation to the ISL23415 is a four byte operation. It
requires first, the CS transition from HIGH-to-LOW. Then host
send a valid Instruction Byte, followed by “dummy” Data Byte,
NOP Instruction Byte and another “dummy” Data Byte to SDI pin.
The SPI host receives the Instruction Byte (instruction code +
register address) and requested Data Byte from SDO pin on the
rising edge of SCK during third and fourth bytes respectively. The
host terminates the read by pulling the CS pin from LOW-to-HIGH
(see Figure 27).
I2
I1
I0
0
0
0
0
0
1
0
1
1
1
0
0
1
1
0
where X means “do not care”.
INSTRUCTION SET
R4
R3
X
X
X
X
X
X
R4
R3
R4
R3
TABLE 4. INSTRUCTION SET
R2
R1
R0
X
X
X
X
X
X
X
X
X
R2
R1
R0
R2
R1
R0
NOP
ACR READ
ACR WRTE
WR or ACR READ
WR or ACR WRTE
OPERATION
CS
SCK
SDI
SDO
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15 16
WR INSTRUCTION
ADDR
DATA BYTE
FIGURE 26. TWO BYTE WRITE SEQUENCE
CS
SCK
SDI
SDO
1
8
RD
ADDR
16
24
32
NOP
RD
ADDR
READ DATA
FIGURE 27. FOUR BYTE READ SEQUENCE
14
FN7780.0
December 15, 2010