MC9S12E128CFUE Datasheet, PDF (134/606 Pages) Freescale Semiconductor, Inc – MC9S12E128 Data Sheet

Chapter 3 Port Integration Module (PIM9E128V1)
3.3.1.6 Port AD Polarity Select Register (PPSAD)
7
R
PPSAD15
W
Reset
0
6
PPSAD14
0
5
PPSAD13
0
4
PPSAD12
0
3
PPSAD11
0
2
PPSAD10
0
1
PPSAD9
0
0
PPSAD8
0
7
R
PPSAD7
W
6
PPSAD6
5
PPSAD5
4
PPSAD4
3
PPSAD3
2
PPSAD2
1
PPSAD1
0
PPSAD0
Reset
0
0
0
0
0
0
0
0
Figure 3-7. Port AD Polarity Select Register (PPSAD)
Read: Anytime. Write: Anytime.
The Port AD Polarity Select Register serves a dual purpose by selecting the polarity of the active interrupt
edge as well as selecting a pull-up or pull-down device if enabled (PERADx = 1). The Port AD Polarity
Select Register is effective only when the corresponding Data Direction Register bit is set to 0 (input).
In pull-down mode (PPSADx = 1), a rising edge on a port AD pin sets the corresponding PIFADx bit. In
pull-up mode (PPSADx = 0), a falling edge on a port AD pin sets the corresponding PIFADx bit.
Table 3-6. PPSAD Field Descriptions
Field
Description
15:0
Polarity Select Port AD
PPSAD[15:0] 0 A pull-up device is connected to the associated port AD pin, and detects falling edge for interrupt generation.
1 A pull-down device is connected to the associated port AD pin, and detects rising edge for interrupt
generation.
MC9S12E128 Data Sheet, Rev. 1.07
134
Freescale Semiconductor