MC9S08EL32 Datasheet, PDF (91/356 Pages) Freescale Semiconductor, Inc – 8-Bit HCS08 Central Processor Unit (CPU)

6.5.3 Port C Registers
Port C is controlled by the registers listed below.
6.5.3.1 Port C Data Register (PTCD)
Chapter 6 Parallel Input/Output Control
R
W
Reset:
7
PTCD7
0
6
PTCD6
5
PTCD5
4
PTCD4
3
PTCD3
2
PTCD2
0
0
0
0
0
Figure 6-19. Port C Data Register (PTCD)
Table 6-17. PTCD Register Field Descriptions
1
PTCD1
0
0
PTCD0
0
Field
Description
7:0
PTCD[7:0]
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.
6.5.3.2 Port C Data Direction Register (PTCDD)
R
W
Reset:
7
PTCDD7
0
6
PTCDD6
5
PTCDD5
4
PTCDD4
3
PTCDD3
2
PTCDD2
0
0
0
0
0
Figure 6-20. Port C Data Direction Register (PTCDD)
Table 6-18. PTCDD Register Field Descriptions
1
PTCDD1
0
0
PTCDD0
0
Field
Description
7:0
Data Direction for Port C Bits — These read/write bits control the direction of port C pins and what is read for
PTCDD[7:0] 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.
MC9S08EL32 Series and MC9S08SL16 Series Data Sheet, Rev. 3
Freescale Semiconductor
91