cat5259 Catalyst Semiconductor, cat5259 Datasheet - Page 10

• Manufacturer Part Number: cat5259
• Description: Quad Digitally Programmable Potentiometers Dpp? With 256 Taps And I?c Interface
• Manufacturer: Catalyst Semiconductor

CAT5259
exchange data between the WCR and one of the Data
Registers. The WCR controls the position of the wiper.
The response of the wiper to this action will be
delayed by t
wiper position), to a Data Register is a write to non-
volatile memory and takes a minimum of t
complete. The transfer can occur between one of the
four potentiometers and one of its associated
registers; or the transfer can occur between all
potentiometers and one associated register.
Four instructions require a two-byte sequence to
complete, as illustrated in Figure 7. These instructions
transfer data between the host/processor and the
CAT5259; either between the host and one of the data
registers or directly between the host and the Wiper
Control Register. These instructions are:
— XFR Data Register to Wiper Control Register
— XFR Wiper Control Register to Data Register
Figure 7. Two-Byte Instruction Sequence
Figure 8. Three-Byte Instruction Sequence
Figure 9. Increment/Decrement Instruction Sequence
Doc. No. MD-2000 Rev. H
SDA
This transfers the contents of one specified
DataRegister to the associated Wiper Control
Register.
This transfers the contents of the specified Wiper
Control Register to the specified associated Data
Register.
SDA
S
T
A
R
T
S
T
A
R
T
ID3 ID2 ID1 ID0
0
WR
ID3 ID2 ID1 ID0
Device ID
0
. A transfer from the WCR (current
1
Device ID
1
SDA
0
0
1
A3
S
T
A
R
T
1
ID3 ID2 ID1 ID0
0
A3
A2
Device ID
1
Internal
Address
Internal
Address
A2 A1 A0
A1 A0 A
0
1
C
K
A3
I3
A
C
K
A2
Internal
Address
Instruction
Opcode
I3
I2
A1
WR
Instruction
Opcode
I1 I0
A0
I2
to
I1
10
A
C
K
R1 R0
Data
Register
Address
I3
I0
— Gang XFR Data Register to Wiper Control
— Gang XFR Wiper Counter Register to Data
INCREMENT/DECREMENT COMMAND
The final command is Increment/Decrement (Figure 9
and 10). The Increment/Decrement command is
different from the other commands. Once the
command is issued and the CAT5259 has responded
with an acknowledge, the master can clock the
selected wiper up and/or down in one segment steps;
thereby providing a fine tuning capability to the host.
For each SCL clock pulse (t
the selected wiper will move one resistor segment
towards the R
pulse while SDA is LOW, the selected wiper will move
one resistor segment towards the RL terminal.
See Instructions format for more detail.
Instruction
Opcode
I2
Data
Register
Address
R1
Register
This transfers the contents of all specified Data
Registers to the associated Wiper Control
Registers.
Register
This transfers the contents of all Wiper Control
Registers to the specified associated Data
Registers.
Address
P1 P0 A
I1
Pot/WCR
R0 P1 P0 A
I0
Pot/WCR
Address
C
K
Register
Address
R1 R0 P1
H
terminal. Similarly, for each SCL clock
D7 D6 D5 D4 D3 D2 D1 D0
C
K
N
C
1
Pot/WCR
Data Register D[7:0]
I
Address
P0
N
C
2
I
WCR[7:0]
Characteristics subject to change without notice
A
C
K
HIGH
or
S
T
O
P
) while SDA is HIGH,
N
C
n
I
© Catalyst Semiconductor, Inc.
D
E
C
1
D
E
C
n
A
C
K
S
O
P
T
S
T
O
P