Datasheet

Chapter 6 Parallel Input/Output Control
MC9S08SH8 MCU Series Data Sheet, Rev. 3
Freescale Semiconductor 89
6.6.3 Port C Registers
Port C is controlled by the registers listed below.
6.6.3.1 Port C Data Register (PTCD)
6.6.3.2 Port C Data Direction Register (PTCDD)
76543210
R0000
PTCD3 PTCD2 PTCD1 PTCD0
W
Reset: 00000000
Figure 6-19. Port C Data Register (PTCD)
Table 6-18. PTCD Register Field Descriptions
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.
76543210
R0000
PTCDD3 PTCDD2 PTCDD1 PTCDD0
W
Reset: 00000000
Figure 6-20. Port C Data Direction Register (PTCDD)
Table 6-19. PTCDD Register Field Descriptions
Field Description
3:0
PTCDD[3:0]
Data Direction for Port C Bits — These read/write bits control the direction of port C pins and what is read for
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.