MC68HC908GP32_08 Datasheet, PDF (28/266 Pages) Freescale Semiconductor, Inc – M68HC08 Microcontrollers

General Description
Decoupling of these pins should be as per the digital supply. See Chapter 4 Analog-to-Digital Converter
(ADC).
V_REFH is the high reference supply for the ADC, and is internally connected to V_DDAD. V_REFL is the low
reference supply for the ADC, and is internally connected to V_SSAD.
1.5.8 Port A Input/Output (I/O) Pins (PTA7/KBD7–PTA0/KBD0)
PTA7–PTA0 are general-purpose, bidirectional I/O port pins. Any or all of the port A pins can be
programmed to serve as keyboard interrupt pins. See Chapter 12 Input/Output (I/O) Ports and Chapter
10 Keyboard Interrupt (KBI) Module.
These port pins also have selectable pullups when configured for input mode. The pullups are disengaged
when configured for output mode. The pullups are selectable on an individual port bit basis.
1.5.9 Port B I/O Pins (PTB7/AD7–PTB0/AD0)
PTB7–PTB0 are general-purpose, bidirectional I/O port pins that can also be used for analog-to-digital
converter (ADC) inputs. See Chapter 12 Input/Output (I/O) Ports and Chapter 4 Analog-to-Digital
Converter (ADC).
1.5.10 Port C I/O Pins (PTC6–PTC0)
PTC6–PTC0 are general-purpose, bidirectional I/O port pins. See Chapter 12 Input/Output (I/O) Ports.
PTC5 and PTC6 are only available on 44-pin QFP package.
These port pins also have selectable pullups when configured for input mode. The pullups are disengaged
when configured for output mode. The pullups are selectable on an individual port bit basis.
1.5.11 Port D I/O Pins (PTD7/T2CH1–PTD0/SS)
PTD7–PTD0 are special-function, bidirectional I/O port pins. PTD0–PTD3 can be programmed to be
serial peripheral interface (SPI) pins, while PTD4–PTD7 can be individually programmed to be timer
interface module (TIM1 and TIM2) pins. See Chapter 17 Timer Interface Module (TIM), Chapter 15 Serial
Peripheral Interface Module (SPI), and Chapter 12 Input/Output (I/O) Ports. PTD6 and PTD7 are only
available on 42-SDIP and 44-pin QFP packages.
These port pins also have selectable pullups when configured for input mode. The pullups are disengaged
when configured for output mode. The pullups are selectable on an individual port bit basis.
1.5.12 Port E I/O Pins (PTE1/RxD–PTE0/TxD)
PTE0–PTE1 are general-purpose, bidirectional I/O port pins. These pins can also be programmed to be
serial communications interface (SCI) pins. See Chapter 13 Serial Communications Interface Module
(SCI) and Chapter 12 Input/Output (I/O) Ports.
MC68HC908GP32 Data Sheet, Rev. 10
28
Freescale Semiconductor