MC68HC08AS20 Datasheet, PDF (33/386 Pages) Freescale Semiconductor, Inc – M68HC08 Microcontrollers

1.5.2 Oscillator Pins (OSC1 and OSC2)
The OSC1 and OSC2 pins are the connections for the on-chip oscillator
circuit. (See Section 8. Clock Generator Module (CGM).)
1.5.3 External Reset Pin (RST)
A logic 0 on the RST pin forces the MCU to a known startup state. RST
is bidirectional, allowing a reset of the entire system. It is driven low when
any internal reset source is asserted. (See Section 9. System
Integration Module (SIM) for more information.)
1.5.4 External Interrupt Pin (IRQ)
IRQ is an asynchronous external interrupt pin. (See Section 14.
External Interrupt (IRQ).)
1.5.5 Analog Power Supply Pin (V_DDA/V_DDAREF)
V_DDA/V_DDAREF is the power supply pin for the analog portion of the chip.
These modules are the analog-to-digital converter (ADC) and the clock
generator module (CGM). (See Section 8. Clock Generator Module
(CGM) and Section 19. Analog-to-Digital Converter (ADC).)
1.5.6 Analog Ground Pin (V_SSA/V_REFL)
The V_SSA/V_REFL analog ground pin is used only for the ground
connections for the analog sections of the circuit and should be
decoupled as per the V_SS digital ground pin. The analog sections consist
of a clock generator module (CGM) and an analog-to-digital converter
(ADC). V_SSA/V_REFL is also the lower reference supply for the ADC. (See
Section 8. Clock Generator Module (CGM) and Section 19.
Analog-to-Digital Converter (ADC).)
MC68HC08AS20 — Rev. 4.1
Freescale Semiconductor
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