CHAPTER 12 A/D CONVERTER
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Block Diagram of the Pins Related to the A/D Converter
Figure 12.3-1 Block Diagram of P03/INT23/AN7 to P00/INT20/AN4 Pins
264
To the A/D
converter
analog input
To an external interrupt
PDR
PDR read
PDR read
(At read-modify-write)
Output
latch
PDR write
DDR
DDR write
Stop mode (SPL = 1)
PUL read
PUL
PUL write
SPL: Pin status setting bit of the standby control register (STBC)
Figure 12.3-2 Block Diagram of P43/AN3 to P40/AN0 Pins
To the A/D
converter
analog input
PDR
PDR read
PDR read
(At read-modify-write)
Output
latch
PDR write
DDR
DDR write
DDR read
OUT read
OUT
OUT write
A/D converter enable bit
A/D converter
(only P00 to P03)
channel select
Pch
Nch
A/D converter
channel select
Stop mode (SPL = 1)
Stop mode
(SPL = 1)
From disabling an
external interrupt
Stop mode (SPL = 1)
Pull-up
resistor
Pins
P00/INT20/AN4
P01/INT21/AN5
P02/INT22/AN6
P03/INT23/AN7
A/D converter
enable bit
Pch
Pins
P40/AN0
Nch
P41/AN1
P42/AN2
P43/AN3