Datasheet

Port C
MC68HC711D3 Data Sheet, Rev. 2.1
Freescale Semiconductor 63
5.4 Port C
Port C is an 8-bit, general-purpose I/O port with a data register (PORTC) and a data direction register
(DDRC). In the single-chip mode, port C pins are general-purpose I/O pins (PC7–PC0). In the
expanded-multiplexed mode, port C pins are configured as multiplexed address/data pins. During the
address cycle, bits 7–0 of the address are output on PC7–PC0. During the data cycle, bits 7–0
(PC7–PC0) are bidirectional data pins controlled by the R/W
signal.
5.4.1 Port C Control Register
CWOM — Port C Wire-OR Mode Bit
1 = Port C outputs are open drain (to facilitate testing)
0 = Port C operates normally
5.4.2 Port C Data Register
PORTC can be read at any time. Inputs return the sensed levels at the pin, while outputs return the input
level of the port C pin drivers. If PORTC is written, the data is stored in an internal latch and can be driven
only if port C is configured for general-purpose outputs in single-chip or bootstrap mode.
Port C pins are general-purpose inputs out of reset in single-chip and bootstrap modes. These pins are
multiplexed low-order address and data bus lines out of reset in expanded-multiplexed and test modes.
5.4.3 Port C Data Direction Register
DDC7–DDC0 — Data Direction Bits for Port C
1 = Corresponding port C pin is configured as output
0 = Corresponding port C pin is configured for input only
Address: $0002
Bit 7654321Bit 0
Read:
00CWOM00000
Write:
Reset:00000000
Figure 5-4. Port C Control Register (PIOC)
Address: $0003
Bit 7654321Bit 0
Read:
PC7 PC6 PC5 PC4 PC3 PC2 PC1 PC0
Write:
Reset:00000000
Figure 5-5. Port C Data Register (PORTC)
Address: $0007
Bit 7654321Bit 0
Read:
DDC7 DDC6 DDC5 DDC4 DDC3 DDC2 DDC1 DDC0
Write:
Reset:00000000
Figure 5-6. Data Direction Register for Port C (DDRC)