EVAL-AD7147EBZ Analog Devices Inc, EVAL-AD7147EBZ Datasheet - Page 34

• Manufacturer Part Number: EVAL-AD7147EBZ
• Description: BOARD EVAL FOR AD7147ACPZ
• Manufacturer: Analog Devices Inc
• Series: CapTouch™r

Specifications of EVAL-AD7147EBZ

• Sensor Type: Touch, Capacitive
• Interface: SPI Serial
• Voltage - Supply: 2.6 V ~ 3.6 V
• Embedded: Yes, MCU, 8-Bit
• Utilized Ic / Part: AD7147
• Silicon Manufacturer: Analog Devices
• Application Sub Type: CapTouch Controller
• Kit Application Type: Data Converter
• Silicon Core Number: AD7147
• Kit Contents: CapTouch Evaluation Board, USB Cable
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Sensitivity: -
• Sensing Range: -
• Lead Free Status / Rohs Status: Compliant

AD7147
SCLK
Reading Data
A read transaction begins when the master writes the command
word to the AD7147 with the read/write bit set to 1. The master
then supplies 16 clock pulses per data-word to be read, and the
AD7147 clocks out data from the addressed register on the SDO
line. The first data-word is clocked out on the first falling edge
of SCLK following the command word, as shown in Figure 51.
SCLK
SDO
SDI
SDI
CS
CS
NOTES
1. MULTIPLE SEQUENTIAL REGISTERS CAN BE LOADED CONTINUOUSLY.
2. THE FIRST (LOWEST ADDRESS) REGISTER ADDRESS IS WRITTEN, FOLLOWED BY MULTIPLE 16-BIT DATA-WORDS.
3. THE ADDRESS AUTOMATICALLY INCREMENTS WITH EACH 16-BIT DATA-WORD (ALL 16 BITS MUST BE WRITTEN).
4. CS IS HELD LOW UNTIL THE LAST DESIRED REGISTER HAS BEEN LOADED.
5. 16-BIT COMMAND WORD SETTINGS FOR SEQUENTIAL WRITE OPERATION:
NOTES
1. SDI BITS ARE LATCHED ON SCLK RISING EDGES. SCLK CAN IDLE HIGH OR LOW BETWEEN WRITE OPERATIONS.
2. THE 16-BIT CONTROL WORD MUST BE WRITTEN ON SDI: 5 BITS FOR ENABLE WORD, 1 BIT FOR R/W, AND 10 BITS FOR REGISTER ADDRESS.
3. THE REGISTER DATA IS READ BACK ON THE SDO PIN.
4. X DENOTES DON’T CARE.
5. XXX DENOTES HIGH IMPEDANCE THREE-STATE OUTPUT.
6. CS IS HELD LOW UNTIL ALL REGISTER BITS HAVE BEEN READ BACK.
7. 16-BIT COMMAND WORD SETTINGS FOR SINGLE READBACK OPERATION:
CW
CW [15:11] = 11100 (ENABLE WORD)
CW [10] = 0 (R/W)
CW [9:0] = [AD9, AD8, AD7, AD6, AD5, AD4, AD3, AD2, AD1, AD0] (STARTING MSB-JUSTIFIED REGISTER ADDRESS)
15
CW [15:11] = 11100 (ENABLE WORD)
CW [10] = 1 (R/W)
CW [9:0] = [AD9, AD8, AD7, AD6, AD5, AD4, AD3, AD2, AD1, AD0] (10-BIT MSB-JUSTIFIED REGISTER ADDRESS)
1
XXX
CW
15
t
ENABLE WORD
CW
2
14
1
t
1
2
XXX
ENABLE WORD
CW
14
CW
13
2
3
t
3
XXX
CW
CW
12
13
4
3
CW
11
XXX
CW
12
5
4
R/W
CW
10
16-BIT COMMAND WORD
XXX
6
CW
11
CW
5
9
7
t
XXX
R/W
CW
4
10
CW
8
6
8
16-BIT COMMAND WORD
XXX
CW
STARTING REGISTER ADDRESS
CW
9
7
7
9
XXX
CW
CW
6
8
10
8
Figure 50. Sequential Register Write SPI Timing
Figure 51. Single Register Readback SPI Timing
CW
XXX
CW
5
7
11
t
5
9
CW
REGISTER ADDRESS
4
XXX
CW
12
6
10
CW
Rev. B | Page 34 of 72
3
13
XXX
CW
5
11
CW
2
14
XXX
CW
4
CW
12
1
15
XXX
CW
CW
3
0
13
The AD7147 continues to clock out data on the SDO line if the
master continues to supply the clock signal on SCLK. The read
transaction finishes when the master takes CS high. If the AD7147
address pointer reaches its maximum value, the AD7147 repeatedly
clocks out data from the addressed register. The address pointer
does not wrap around.
16
D15 D14
XXX
CW
2
17
14
DATA FOR STARTING
REGISTER ADDRESS
XXX
CW
18
1
15
XXX
CW
0
16
D15
X
D1
17
31
t
6
D14
X
D0
18
32
D15
16-BIT READBACK DATA
D13
X
33
19
D14
REGISTER ADDRESS
34
DATA FOR NEXT
D2
X
30
D1
47
D1
X
t
D0
31
8
48
t
7
D0
D15
X
49
32
XXX