MC9S12KG128 Datasheet, PDF (154/600 Pages) Freescale Semiconductor, Inc – Microcontrollers

Chapter 4 Port Integration Module (PIM9KG128V1)
4.3.3.5 Port M Pull Device Enable Register (PERM)
Module Base + 0x0014
7
R
PERM7
W
6
PERM6
5
PERM5
4
PERM4
3
PERM3
2
PERM2
1
PERM1
0
PERM0
Reset
0
0
0
0
0
0
0
0
Figure 4-19. 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, if the port is used as input or
wired-OR output. This bit has no effect if the port is used as push-pull output. Out of reset no pull device
is enabled.
Table 4-14. PERM Field Descriptions
Field
Description
7–0
Pull Device Enable Port M
PERM[7:0] 0 Pull-up or pull-down device is disabled.
1 Either a pull-up or pull-down device is enabled.
4.3.3.6 Port M Polarity Select Register (PPSM)
Module Base + 0x0015
R
W
Reset
7
PPSM7
0
6
PPSM6
0
5
PPSM5
0
4
PPSM4
0
3
PPSM3
0
2
PPSM2
0
Figure 4-20. Port M Polarity Select Register (PPSM)
Read: Anytime. Write: Anytime.
1
PPSM1
0
0
PPSM0
0
This register selects whether a pull-down or a pull-up device is connected to the pin. If CAN is active a
pull-up device can be activated on the receiver inputs, but not a pull-down.
Table 4-15. PPSM Field Descriptions
Field
Description
7–0
PPSM[7:0]
Pull Select Port M
0 A pull-up device is connected to the associated port M pin, if enabled by the associated bit in register PERM
and if the port is used as general purpose, RXCAN input.
1 A pull-down device is connected to the associated port M pin, if enabled by the associated bit in register PERM
and if the port is used as a general purpose but not as RXCAN.
MC9S12KG128 Data Sheet, Rev. 1.15
154
Freescale Semiconductor