mc68hc05p18a Freescale Semiconductor, Inc, mc68hc05p18a Datasheet - Page 58

• Manufacturer Part Number: mc68hc05p18a
• Description: Mc68hc05p18a Hcmos Microcontroller Unit
• Manufacturer: Freescale Semiconductor, Inc

Input/Output (I/O) Ports
7.5 Port C
Technical Data
INTERNAL HC05
DATA BUS
CAUTION:
WRITE $0006
WRITE $0002
READ $0006
READ $0002
RESET
Port C is an 8-bit bidirectional port that can share pins PC3–PC7 with the
analog-to-digital (A/D) converter subsystem. The port C data register is
located at address $0002 and its data direction register (DDR) is located
at address $0006. Reset does not affect the data registers, but clears the
DDRs, thereby setting all of the port pins to input mode. Writing a 1 to a
DDR bit sets the corresponding port pin to output mode (see
Figure
higher current than a typical I/O pin. See
Specifications
Port C may be used for general I/O applications when the A/D
subsystem is disabled. The ADON bit in the A/D status and control
register (ADSC) is used to enable/disable the A/D subsystem.
Care must be exercised when using pins PC0–PC2 while the A/D
subsystem is enabled. Accidental changes to bits that affect pins
PC3–PC7 in the data or DDR registers will produce unpredictable results
in the A/D subsystem.
See
(RST)
Freescale Semiconductor, Inc.
Section 11. Analog-to-Digital (A/D)
For More Information On This Product,
7-3). Two port C pins, PC0 and PC1, can source and sink a
Figure 7-3. Port C I/O Circuitry
DATA DIRECTION
REGISTER BIT
REGISTER BIT
Go to: www.freescale.com
DATA
Input/Output (I/O) Ports
regarding current specifications.
Section 13. Electrical
Converter.
OUTPUT
CAPABILITY, PC0
HIGH CURRENT
AND PC1 ONLY
MC68HC05P18A
PIN
I/O