MC9S08SG8 Datasheet, PDF (86/310 Pages) Freescale Semiconductor, Inc – Microcontrollers

Chapter 6 Parallel Input/Output Control
6.6.3 Port C Registers
Port C is controlled by the registers listed below.
6.6.3.1 Port C Data Register (PTCD)
7
R
0
W
Reset:
0
6
5
4
3
2
0
0
0
PTCD3
PTCD2
0
0
0
0
0
Figure 6-19. Port C Data Register (PTCD)
Table 6-18. PTCD Register Field Descriptions
1
PTCD1
0
0
PTCD0
0
Field
Description
3:0
PTCD[3:0]
Port C Data Register Bits — For port C pins that are inputs, reads return the logic level on the pin. For port C
pins that are configured as outputs, reads return the last value written to this register.
Writes are latched into all bits of this register. For port C pins that are configured as outputs, the logic level is
driven out the corresponding MCU pin.
Reset forces PTCD to all 0s, but these 0s are not driven out the corresponding pins because reset also
configures all port pins as high-impedance inputs with pull-ups disabled.
6.6.3.2 Port C Data Direction Register (PTCDD)
7
R
0
W
Reset:
0
6
5
4
3
2
0
0
0
PTCDD3 PTCDD2
0
0
0
0
0
Figure 6-20. Port C Data Direction Register (PTCDD)
Table 6-19. PTCDD Register Field Descriptions
1
PTCDD1
0
0
PTCDD0
0
Field
Description
3:0
Data Direction for Port C Bits — These read/write bits control the direction of port C pins and what is read for
PTCDD[3:0] PTCD reads.
0 Input (output driver disabled) and reads return the pin value.
1 Output driver enabled for port C bit n and PTCD reads return the contents of PTCDn.
MC9S08SG8 MCU Series Data Sheet, Rev. 0
86
PRELIMINARY
Freescale Semiconductor