MC68HC11F1 Datasheet, PDF (33/68 Pages) Motorola, Inc – Technical Summary 8-Bit Microcontroller

7 Parallel Input/Output
On the MC68HC11F1, either 54 or 51 pins are available for general-purpose I/O, depending on the
package. These pins are arranged into ports A, B, C, D, E, F, and G. On the MC68HC11FC0, either 52
or 49 pins are available, depending on the package.
I/O functions on some ports (B, C, F, and G) are affected by the mode of operation selected. In the sin-
gle-chip and bootstrap modes, they are configured as parallel I/O data ports. In expanded and test
modes, they are configured as follows:
• Ports B and F are configured as the address bus.
• Port C is configured as the data bus.
• Port G bit 7 is configured as the optional program chip select CSPROG.
In addition, in expanded and test modes the R/W signal is configured as data bus direction control. The
remaining ports (A, D, and E) are unaffected by mode changes.
7.1 Port A
Port A is an eight-bit general-purpose I/O port (PA[7:0]) with a data register (PORTA) and a data direc-
tion register (DDRA). Port A pins are available for shared use among the main timer, pulse accumulator,
and general I/O functions, regardless of mode. Four pins can be used for timer output compare func-
tions (OC), three for input capture (IC), and one as either a fourth IC or a fifth OC.
7.2 Port B
Port B is an eight-bit general-purpose output-only port in single-chip modes. In expanded modes, port
B pins act as high-order address lines ADDR[15:8], and accesses to PORTB (the port B data register)
are mapped externally.
7.3 Port C
Port C is an eight-bit general-purpose I/O port with a data register (PORTC) and a data direction register
(DDRC). In single-chip modes, port C pins are general-purpose I/O pins PC[7:0]. Port C can be config-
ured for wired-OR operation in single-chip modes by setting the CWOM bit in the OPT2 register. In ex-
panded modes, port C is the data bus DATA[7:0], and accesses to PORTC (the port C data register)
are mapped externally.
7.4 Port D
Port D is a six-bit general-purpose I/O port with a data register (PORTD) and a data direction register
(DDRD). In all modes, the six port D lines (PD[5:0]) can be used for general-purpose I/O or for the serial
communications interface (SCI) or serial peripheral interface (SPI) subsystems. Port D can also be con-
figured for wired-OR operation.
7.5 Port E
Port E is an eight-bit input-only port that is also used (on the MC68HC11F1 only) as the analog input
port for the analog-to-digital converter. Port E pins that are not used for the A/D system can be used as
general-purpose inputs. However, PORTE should not be read during the sample portion of an A/D con-
version sequence.
NOTE
PE7 and PE0 are not available on the 80-pin MC68HC11FC0. PE7, PE4, and PE0
are not available on the 64-pin MC68HC11FC0.
7.6 Port F
Port F is an eight-bit output-only port. In single-chip mode, port F pins are general-purpose output pins
PF[7:0]. In expanded mode, port F pins act as low-order address outputs ADDR[7:0].
MC68HC11F1/FC0
MC68HC11FTS/D
MOTOROLA
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