MC912DG128ACPVE Datasheet, PDF (45/478 Pages) Freescale Semiconductor, Inc – Upward compatible with M68HC11 instruction set

Freescale Semiconductor, Inc.
Pinout and Signal Descriptions
Power Supply Pins
3.3 Power Supply Pins
MC68HC912DT128A power and ground pins are described below and
summarized in Table 3-1.
All power supply pins must be connected to appropriate supplies.
On no account must any pins be left floating.
3.3.1 Internal Power (V_DD) and Ground (V_SS)
Power is supplied to the MCU through V_DD and V_SS. Because fast signal
transitions place high, short-duration current demands on the power
supply, use bypass capacitors with high-frequency characteristics and
place them as close to the MCU as possible.
3.3.2 External Power (V_DDX) and Ground (V_SSX)
External power and ground for I/O drivers. Because fast signal
transitions place high, short-duration current demands on the power
supply, use bypass capacitors with high-frequency characteristics and
place them as close to the MCU as possible. Bypass requirements
depend on how heavily the MCU pins are loaded.
3.3.3 V_DDA, V_SSA
Provides operating voltage and ground for the analog-to-digital
converter. This allows the supply voltage to the A/D to be bypassed
independently.
3.3.4 Analog to Digital Reference Voltages (V_RH, V_RL)
V_RH0, V_RL0: reference voltage high and low for ATD converter 0.
V_RH1, V_RL1: reference voltage high and low for ATD converter 1.
If the ATD modules are not used, leaving V_RH connected to V_DD will not
result in an increase of power consumption.
MC68HC912DT128A — Rev 4.0
MOTOROLA
Pinout and Signal Descriptions
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Technical Data
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