
[AK4673]
MS0670-E-00
2007/09
- 76 -
■
Control Command
The control command, 8 bits, provided to the AK4673 via SDA, is shown in the following table. This command includes
start bit, channel selection bit, power-down bit and resolution bit. The AK4673 latches the serial command at the rising
edge of SCL. Refer to the detailed information regarding the bit order, function, the status of driver switch, ADC input as
shown in
Table 60
.
BIT
Name
7
S
Start Bit. “1” Accelerate and Axis Command, “0”: Sleep mode Command
6-4
A2-A0
Channel Selection Bits. Analog inputs to the A/D converter and the activated driver switches
are selected. Please see the following table for the detail.
3
X1
Don’t care
2
PD0
Power down bit (refer to power-down control)
1
MODE
Resolution of A/D converter. “0”: 12 bit output “1”: 8 bit output when S bit is “1”.
Sleep mode selection when S bit is “0”.
0
X2
Don’t care
Input
Status of Driver Switch
Function
ADC input
(
Δ
AIN)
Reference
Voltage
(
Δ
VREF)
VREF+
S
A2
A1
A0
XP
XN
YP
YN
AIN+
AIN-
VREF
-
XN
Note
0
1
1
0
1
0
1
0
Sleep
Accelerate
X-Driver
Accelerate
Y-Driver
Accelerate Y+,
X- Driver
X-axis
Y-axis
Z1 (Pen Pressure)
Z2 (Pen Pressure)
ON
ON
OFF
OFF
YP
XN
XP
1
0
0
1
OFF OFF
ON
ON
XP
YN
YP
YN
1
1
1
1
1
1
0
0
1
1
1
1
1
1
0
0
1
1
0
1
0
1
0
1
OFF
OFF
ON
OFF OFF
OFF
OFF
ON
ON
ON
ON
ON
OFF
ON
ON
ON
OFF
OFF
OFF
ON
OFF
OFF
XP
YN
YP
XP
XN
XN
XN
YN
XN
XN
YP
YP
XP
YP
YP
YP
XN
XN
XN
YN
XN
XN
ON
ON
XP (Z1)
YN
(Z2)
Table 60 Control Command List
■
Power-down Control
A/D converter and power-down control of touch driver switch are determined by PD0 bit.
PD0
PENIRQN
0
Enabled
Auto power-down Mode
A/D converter is automatically powered up at the start of the conversion, and goes to
power- down state automatically at the end of the conversion. All touch screen driver
switches except for YN switch are turned off and relative pins are open state. Only YN
driver switch is turned ON and the YN pin is forced to the ground in this case. PEN
interrupt function is enabled except for the sampling time and conversion time.
1
Disabled
ADC ON Mode
When X-axis or Y-axis are selected on the write operation with PD0 = “1” A/D converter
and touch panel driver are always powered up until next conversion. This mode is
effective if more settling time is required to suppress the electrical bouncing of touch
plate.
PEN interrupt function is disabled and PENIRQN is forced to “L” state
Table 61 Power –Down Control
Function