S912XEG384J3VA Datasheet, PDF (135/1324 Pages) Freescale Semiconductor, Inc – MC9S12XEP100 Reference Manual Covers MC9S12XE Family

2.3.42
Chapter 2 Port Integration Module (S12XEPIMV1)
Port M Polarity Select Register (PPSM)
Address 0x0255
R
W
Reset
7
PPSM7
0
1. Read: Anytime.
Write: Anytime.
6
PPSM6
5
PPSM5
4
PPSM4
3
PPSM3
2
PPSM2
0
0
0
0
0
Figure 2-40. Port M Polarity Select Register (PPSM)
Access: User read/write⁽¹⁾
1
0
PPSM1
PPSM0
0
0
Table 2-38. PPSM Register Field Descriptions
Field
7-0
PPSM
Description
Port M pull device select—Determine pull device polarity on input pins
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 RXCAN[3:0] inputs, but not a pull-down.
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.
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 or RXCAN input.
2.3.43 Port M Wired-Or Mode Register (WOMM)
Address 0x0256
R
W
Reset
7
WOMM7
0
1. Read: Anytime.
Write: Anytime.
6
WOMM6
5
WOMM5
4
WOMM4
3
WOMM3
2
WOMM2
0
0
0
0
0
Figure 2-41. Port M Wired-Or Mode Register (WOMM)
Access: User read/write⁽¹⁾
1
0
WOMM1 WOMM0
0
0
Table 2-39. WOMM Register Field Descriptions
Field
Description
7-0
WOMM
Port M wired-or mode—Enable wired-or functionality
This register configures the output pins as wired-or independent of the function used on the pins. If enabled the
output is driven active low only (open-drain). A logic level of “1” is not driven.This allows a multipoint connection of
several serial modules. These bits have no influence on pins used as inputs.
1 Output buffers operate as open-drain outputs.
0 Output buffers operate as push-pull outputs.
MC9S12XE-Family Reference Manual Rev. 1.25
Freescale Semiconductor
135