Datasheet

Chapter 6 Parallel Input/Output
MC9S08LC60 Series Data Sheet: Technical Data, Rev. 4
Freescale Semiconductor 91
6.2.5.1 Port C Data Registers (PTCD)
Port C parallel I/O function is controlled by the data and data direction registers in this section.
6.2.5.2 Port C Data Direction Registers (PTCDD)
6.2.6 Port C Control Registers
Associated with the parallel I/O ports is a set of registers located in the high page register space that operate
independently of the parallel I/O registers. These registers are used to control pullups, slew rate, and drive
76543210
R
PTCD7
1
1
Reads of PTCD7 always return the pin value of PTC7, regardless of the value stored in the bit PTCDD7
PTCD6
2
2
Reads of PTCD6 always return the contents of PTCD6, regardless of the value stored in the bit PTCDD6.
PTCD5 PTCD4 PTCD3 PTCD2 PTCD1 PTCD0
W
Reset 00000000
Figure 6-18. Port C Data Register (PTCD)
Table 6-11. PTCD Field Descriptions
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 pullups disabled.
76543210
R
PTCDD7
1
1
PTCDD7 has no effect on the input-only PTC7 pin.
PTCDD6
2
2
PTCDD6 has no effect on the output-only PTC6 pin
PTCDD5 PTCDD4 PTCDD3 PTCDD2 PTCDD1 PTCDD0
W
Reset 00000000
Figure 6-21. Data Direction for Port C (PTCDD)
Table 6-12. PTCDD Field Descriptions
Field Description
7:0
PTCDD[7:0]
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.