mpr083 Freescale Semiconductor, Inc, mpr083 Datasheet - Page 17

• Manufacturer Part Number: mpr083
• Description: Proximity Capacitive Touch Sensor Controller
• Manufacturer: Freescale Semiconductor, Inc

Sensors
Freescale Semiconductor
6
6.1
The MPR083 has three primary methods for reporting data in addition to an IRQ output that is described in Chapter 7. The three
output systems are described in this section.
6.2
The Instantaneous output shows the current status of the user interface. This information is displayed in terms of the current
rotary position that is touched. Only one touch can be shown at a time.
6.2.1
The Rotary Status Register is a read only register for determining the current status of the rotary. The I
Rotary Status Register is 0x02.
6.3
The Buffered output is done through a FIFO. The FIFO will buffer every touch that occurs up to 30 values before the buffer
overflows and data is lost. Any time data is read from the FIFO it is pulled from the buffer and the next item becomes available.
The buffer can be cleared (NDF goes high) by either reading the last entry or attempting to write to the register.
The buffer settings are configured in the Rotary Configuration Register as described in
6.3.1
The FIFO Register is a read only register for determining the current status of the rotary. Any time a write is issued to this register
the buffer will be cleared. The I
Table 12. Rotary Status Register Field Descriptions
Output Mechanisms
Introduction
Instantaneous
Rotary Status Register
Buffered
FIFO Register
Reset:
Reset:
Field
3:0
CP
SF
W
W
4
R
R
MDF
7
0
0
7
0
2
C slave address of the FIFO Register is 0x00.
= Unimplemented
= Unimplemented
Status Flag – The Status Flag shows when the rotary is currently detecting a touch.
0 Rotary is not currently detecting a touch
1 Rotary is currently detecting a touch
Current Position – The Current Position represents the electrode that is currently
being touched.
0000 Encoding 0 – Electrode 1 is currently touched
~
0111 Encoding 7 – Electrode 8 is currently touched
NDF
6
0
0
6
1
Figure 20. Rotary Status Register
Figure 21. FIFO Register
OF
5
0
0
5
0
TRF
SF
4
0
4
0
Description
3
0
3
0
2
0
2
0
Section
CP
BP
3.4.
1
0
1
0
2
C slave address of the
0
0
0
0
MPR083
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