MC68HC908GR8A_07 Datasheet, PDF (24/260 Pages) Freescale Semiconductor, Inc – Microcontrollers

General Description
1.5.5 CGM Power Supply Pins (V_DDA and V_SSA)
V_DDA and V_SSA are the power supply pins for the analog portion of the clock generator module (CGM).
Decoupling of these pins should be as per the digital supply. See Chapter 4 Clock Generator Module
(CGM).
1.5.6 External Filter Capacitor Pin (V_CGMXFC)
CGMXFC is an external filter capacitor connection for the CGM. See Chapter 4 Clock Generator Module
(CGM).
1.5.7 ADC Power Supply/Reference Pins (V_DDAD/V_REFH and V_SSAD/V_REFL)
V_DDAD and V_SSAD are the power supply pins to the analog-to-digital converter (ADC). V_REFH and V_REFL
are the reference voltage pins for the ADC. V_REFH is the high reference supply for the ADC, and by default
the V_DDAD/V_REFH pin should be externally filtered and connected to the same voltage potential as V_DD.
V_REFL is the low reference supply for the ADC, and by default the V_SSAD/V_REFL pin should be connected
to the same voltage potential as V_SS. See Chapter 3 Analog-to-Digital Converter (ADC).
1.5.8 Port A Input/Output (I/O) Pins (PTA3/KBD3–PTA0/KBD0)
PTA3–PTA0 are special-function, 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 9
Keyboard Interrupt Module (KBI).
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 (PTB5/AD5–PTB0/AD0)
PTB5–PTB0 are special-function, 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 3 Analog-to-Digital
Converter (ADC).
1.5.10 Port C I/O Pins (PTC1 and PTC0)
PTC1 and PTC0 are general-purpose, bidirectional I/O port pins. PTC1–PTC0 are only available on the
32-pin LQFP package. See Chapter 12 Input/Output (I/O) Ports.
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 (PTD6/T2CH0–PTD0/SS)
PTD6–PTD0 are special-function, bidirectional I/O port pins. PTD3–PTD0 can be programmed to be
serial peripheral interface (SPI) pins, while PTD6–PTD4 can be individually programmed to be timer
interface module (TIM1 and TIM2) pins. See Chapter 17 Timer Interface Module (TIM1 and TIM2),
Chapter 15 Serial Peripheral Interface (SPI) Module, and Chapter 12 Input/Output (I/O) Ports.
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.
MC68HC908GR8A • MC68HC908GR4A Data Sheet, Rev. 5
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Freescale Semiconductor