UM10503
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User manual
Rev. 1.3 — 6 July 2012
298 of 1269
NXP Semiconductors
UM10503
Chapter 15: LPC43xx System Control Unit (SCU)/ IO configuration
15.4.7 ADC1 function select register
For pins with digital and analog functions, this register selects the ADC1 function over any
of the possible digital functions.
In addition, each analog function is pinned out on a dedicated analog pin which is not
affected by this register.
The following pins are controlled by the ENAIO1 register:
By default, all pins are connected to their digital function 0 and only the digital pad is
available.
To select the analog function, the pad must be set as follows using the corresponding
SFSP register:
1. Tri-state the output driver by selecting an input at the pinmux e.g. GPIO function in
input mode.
2. Disable the receiver by setting the EZI bit to zero (see
or
the default setting.
3. Disable the pull-up resistor by setting the EPUN bit to one, and disable the pull-down
resistor by setting the EPD bit to zero.
4. Set the bit corresponding to the analog function to 1 in the ENAIO1 register.
6
ADC0_6
Select ADC0_6
0
R/W
0
Digital function selected on pin PB_6.
1
Analog function ADC0_6 selected on pin PB_6.
31:7
Reserved
-
-
Table 139. ADC0 function select register (ENAIO0, address 0x4008 6C88) bit description
Bit
Symbol
Value Description
Reset
value
Access
Table 140. Pins controlled by the ENAIO1 register
Pin
ADC function
ENAIO1 register bit
PC_3
ADC1_0
0
PC_0
ADC1_1
1
PF_9
ADC1_2
2
PF_6
ADC1_3
3
PF_5
ADC1_4
4
PF_11
ADC1_5
5
P7_7
ADC1_6
6
PF_7
ADC1_7
7
Table 141. ADC1 function select register (ENAIO1, address 0x4008 6C8C) bit description
Bit
Symbol
Value Description
Reset
value
Access
0
ADC1_0
Select ADC1_0
0
R/W
0
Digital function selected on pin PC_3.
1
Analog function ADC1_0 selected on pin PC_3.