UM10503
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© NXP B.V. 2012. All rights reserved.
User manual
Rev. 1.3 — 6 July 2012
299 of 1269
NXP Semiconductors
UM10503
Chapter 15: LPC43xx System Control Unit (SCU)/ IO configuration
15.4.8 Analog function select register
For pins which have digital and analog functions, this register selects the analog DAC and
band gap function over any of the possible digital functions.
In addition, the DAC function is pinned out on a dedicated analog pin which is not affected
by this register.
The following pins are controlled by the ENAIO2 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
ADC1_1
Select ADC1_1
0
R/W
0
Digital function selected on pin PC_0.
1
Analog function ADC1_1 selected on pin PC_0.
2
ADC1_2
Select ADC1_2
0
R/W
0
Digital function selected on pin PF_9.
1
Analog function ADC1_2 selected on pin PF_9.
3
ADC1_3
Select ADC1_3
0
R/W
0
Digital function selected on pin PF_6.
1
Analog function ADC1_3 selected on pin PF_6.
4
ADC1_4
Select ADC1_4
0
R/W
0
Digital function selected on pin PF_5.
1
Analog function ADC1_4 selected on pin PF_5.
5
ADC1_5
Select ADC1_5
0
R/W
0
Digital function selected on pin PF_11.
1
Analog function ADC1_5 selected on pin PF_11.
6
ADC1_6
Select ADC1_6
0
R/W
0
Digital function selected on pin P7_7.
1
Analog function ADC1_6 selected on pin P7_7.
7
ADC1_7
Select ADC1_7.
0
R/W
0
Digital function selected on pin PF_7.
1
Analog function ADC1_7 selected on pin PF_7.
31:8
Reserved
-
-
Table 141. ADC1 function select register (ENAIO1, address 0x4008 6C8C) bit description
Bit
Symbol
Value Description
Reset
value
Access
Table 142. Pins controlled by the ENAIO2 register
Pin
ADC function
ENAIO2 register bit
P4_4
DAC
0
PF_7
BG (band gap output)
4