MPR121_10 FREESCALE [Freescale Semiconductor, Inc], MPR121_10 Datasheet - Page 44
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MPR121_10
Manufacturer Part Number
MPR121_10
Description
Proximity Capactive touch Senosr controller
Manufacturer
FREESCALE [Freescale Semiconductor, Inc]
Datasheet
1.MPR121_10.pdf
(57 pages)
MPR121
44
can write always regardless Shutdown and Run mode.
EN[7:0], DIR[7:0], CTL0[7:0], CTL1[7:0]: Configuration Register
Configuration register (0x5E) and GPIO Enable Register (0x77), but electrode configuration has higher priority than GPIO fea-
ture. When a pin is enabled as GPIO but is also selected as electrode by Electrode Configuration Register, the GPIO function is
disabled immediately and it becomes an electrode during Run mode. But all 8 ports automatically become GPIO ports in Shut-
down mode because none of the ports are being enabled as touch electrodes in Shutdown mode.
disabled. Take care to program unused ports which are not going to be used as either touch electrodes or GPIO to avoid floating
inputs or outputs shorted to a rail. One approach is to enable unused ports to be GPIO inputs with internal pull-up or pull-down.
Table 44. GPIO Control Registers
GPIO Control 0
GPIO Control 1
GPIO Data
GPIO Direction
GPIO Enable
GPIO Data Set
GPIO Data Clear
GPIO Data Toggle
These registers control GPIO function. D7~D0 bits corresponds GPIO7~GPIO0 pins respectively. The GPIO control registers
The number of touch sensing electrodes (and therefore the number of GPIO ports available) is configured by the Electrode
During the shutdown mode just after power on reset, all 8 GPIO ports are in high impedance as all the GPIO ports are default
Name
Address
Figure 47. Configuration 2: MPR121 runs from a 2.5 V to 3.6 V supply.
2.5 V to 3.6 V
0x7A
0x73
0x74
0x75
0x76
0x77
0x78
0x79
VDD
CTL0[7]
CTL1[7]
TOG[7]
DAT[7]
CLR[7]
SET[7]
DIR[7]
EN[7]
D7
GND
CTL0[6]
CTL1[6]
0.1 μF
TOG[6]
DAT[6]
SET[6]
CLR[6]
DIR[6]
EN[6]
D6
0.1 μF
GND
2.5 V to 3.6 V
VDD
CTL0[5]
CTL1[5]
TOG[5]
DAT[5]
SET[5]
CLR[5]
DIR[5]
EN[5]
75 kΩ 1%
GND
D5
20
6
5
1
2
3
4
7
VDD
VSS
VREG
IRQ
SCL
SDA
ADDR
REXT
CTL0[4]
CTL1[4]
TOG[4]
DAT[4]
CLR[4]
SET[4]
DIR[4]
EN[4]
D4
TOUCH SENSOR
MPR121Q
CTL0[3]
CTL1[3]
TOG[3]
DAT[3]
SET[3]
CLR[3]
DIR[3]
EN[3]
D3
ELE11/LED7
ELE10/LED6
ELE9/LED5
ELE8/LED4
ELE7/LED3
ELE6/LED2
ELE5/LED1
ELE4/LED0
ELE3
ELE2
ELE1
ELE0
CTL0[2]
CTL1[2]
TOG[2]
DAT[2]
SET[2]
CLR[2]
DIR[2]
EN[2]
D2
Freescale Semiconductor
19
18
17
16
14
13
12
11
10
9
8
15
CTL0[1]
CTL1[1]
TOG[1]
DAT[1]
SET[1]
CLR[1]
DIR[1]
EN[1]
D1
CTL0[0]
CTL1[0]
TOG[0]
Sensors
DAT[0]
SET[0]
CLR[0]
DIR[0]
EN[0]
D0