S912XEG128J2MAA Datasheet, PDF (110/1324 Pages) Freescale Semiconductor, Inc – Microcontrollers

Chapter 2 Port Integration Module (S12XEPIMV1)
Table 2-7. DDRB Register Field Descriptions
Field
7-0
DDRB
Description
Port B Data Direction—
This register controls the data direction of pins 7 through 0.
The external bus function forces the I/O state to be outputs for all associated pins. In this case the data direction bits
will not change.
When operating a pin as a general purpose I/O, the associated data direction bit determines whether it is an input
or output.
1 Associated pin is configured as output.
0 Associated pin is configured as high-impedance input.
2.3.7 Port C Data Register (PORTC)
Address 0x0004 (PRR)
Access: User read/write⁽¹⁾
7
R
PC7
W
6
PC6
5
PC5
4
PC4
3
PC3
2
PC2
1
PC1
0
PC0
Altern.
Function
DATA15
DATA14
DATA13
DATA12
DATA11
DATA10
DATA9
DATA8
Reset
0
0
0
0
0
0
0
0
Figure 2-5. Port C Data Register (PORTC)
1. Read: Anytime. In emulation modes, read operations will return the data from the external bus, in all other modes the data source
is depending on the data direction value.
Write: Anytime. In emulation modes, write operations will also be directed to the external bus.
Field
7-0
PC
Table 2-8. PORTC Register Field Descriptions
Description
Port C general purpose input/output data—Data Register
Port C pins 7 through 0 are associated with data I/O lines DATA[15:8] respectively in expanded modes.
When not used with the alternative function, these pins can be used as general purpose I/O.
If the associated data direction bits of these pins are set to 1, a read returns the value of the port register, otherwise
the buffered pin input state is read.
MC9S12XE-Family Reference Manual Rev. 1.25
110
Freescale Semiconductor