MC9S12HZ256 Datasheet, PDF (136/692 Pages) Freescale Semiconductor, Inc – HCS12 Microcontrollers

Chapter 4 Port Integration Module (PIM9HZ256V2)
4.3.3.5 Port M Pull Device Enable Register (PERM)
7
6
5
4
3
2
1
0
R
0
0
0
0
PERM5
PERM4
PERM3
PERM2
W
Reset
0
0
0
0
0
0
0
0
= Reserved or Unimplemented
Figure 4-20. Port M Pull Device Enable Register (PERM)
Read: Anytime. Write: Anytime.
This register configures whether a pull-up or a pull-down device is activated on configured input or
wired-or output pins. If a pin is configured as push-pull output, the corresponding Pull Device Enable
Register bit has no effect.
Table 4-15. PERM Field Descriptions
Field
5:2
Pull Device Enable Port M
PERM[5:2] 0 Pull-up or pull-down device is disabled.
1 Pull-up or pull-down device is enabled.
Description
4.3.3.6 Port M Polarity Select Register (PPSM)
7
6
5
4
3
2
1
0
R
0
0
0
0
PPSM5
PPSM4
PPSM3
PPSM2
W
Reset
0
0
0
0
0
0
0
0
= Reserved or Unimplemented
Figure 4-21. Port M Polarity Select Register (PPSM)
Read: Anytime. Write: Anytime.
The Port M Polarity Select Register selects whether a pull-down or a pull-up device is connected to the
pin. The Port M Polarity Select Register is effective only when the corresponding Data Direction Register
bit is set to 0 (input) and the corresponding Pull Device Enable Register bit is set to 1.
If a CAN module is enabled, a pull-up device can be activated on the receiver pin, and on the transmitter
pin if the corresponding wired-OR mode bit is set. Pull-down devices can not be activated on CAN pins.
MC9S12HZ256 Data Sheet, Rev. 2.04
136
Freescale Semiconductor