MC68HC908AS32A Datasheet, PDF (24/280 Pages) Freescale Semiconductor, Inc – Microcontrollers

General Description
MCU
V_DD
V_SS
C1
0.1 µF
+
C2
V_DD
NOTE: Component values shown represent typical applications.
Figure 1-4. Power Supply Bypassing
V_SS is also the ground for the port output buffers and the ground return for the serial clock in the SPI. See
Chapter 16 Serial Peripheral Interface (SPI) for more information.
NOTE
V_SS must be grounded for proper MCU operation.
1.4.2 Oscillator Pins (OSC1 and OSC2)
The OSC1 and OSC2 pins are the connections for the on-chip oscillator circuit. See Chapter 5 Clock
Generator Module (CGM) for more information.
1.4.3 External Reset Pin (RST)
A 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 Chapter 15 System
Integration Module (SIM) for more information.
1.4.4 External Interrupt Pin (IRQ)
IRQ is an asynchronous external interrupt pin. See Chapter 10 External Interrupt Module (IRQ) for more
information.
1.4.5 External Filter Capacitor Pin (CGMXFC)
CGMXFC is an external filter capacitor connection for the clock generator module (CGM). See Chapter 5
Clock Generator Module (CGM) for more information.
1.4.6 Analog Power Supply Pin (V_DDA/V_DDAREF)
V_DDA/V_DDAREF is the power supply pin for the analog portion of the ADC and the CGM. See Chapter 3
Analog-to-Digital Converter (ADC) and Chapter 5 Clock Generator Module (CGM) for more information.
MC68HC908AS32A Data Sheet, Rev. 2.0
24
Freescale Semiconductor