mc68hc912dg128 Freescale Semiconductor, Inc, mc68hc912dg128 Datasheet - Page 448

• Manufacturer Part Number: mc68hc912dg128
• Description: M68hc12 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

Glossary
program counter (PC) — A 16-bit register in the CPU. The PC register holds the address of the
pull — An instruction that copies into the accumulator the contents of a stack RAM location. The
pullup — A transistor in the output of a logic gate that connects the output to the logic 1 voltage
pulse-width — The amount of time a signal is on as opposed to being in its off state.
pulse-width modulation (PWM) — Controlled variation (modulation) of the pulse width of a
push — An instruction that copies the contents of the accumulator to the stack RAM. The stack
PWM period — The time required for one complete cycle of a PWM waveform.
RAM — Random access memory. All RAM locations can be read or written by the CPU. The
RC circuit — A circuit consisting of capacitors and resistors having a defined time constant.
read — To copy the contents of a memory location to the accumulator.
register — A circuit that stores a group of bits.
reserved memory location — A memory location that is used only in special factory test modes.
reset — To force a device to a known condition.
SCI — See "serial communication interface module (SCI)."
serial — Pertaining to sequential transmission over a single line.
serial communications interface module (SCI) — A module that supports asynchronous
serial peripheral interface module (SPI) — A module that supports synchronous
set — To change a bit from logic 0 to logic 1; opposite of clear.
Technical Data
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next instruction or operand that the CPU will use.
stack RAM address is in the stack pointer.
of the power supply.
signal with a constant frequency.
RAM address is in the stack pointer.
contents of a RAM memory location remain valid until the CPU writes a different value or
until power is turned off.
Writing to a reserved location has no effect. Reading a reserved location returns an
unpredictable value.
communication.
communication.
Freescale Semiconductor, Inc.
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Glossary
MC68HC912DG128 — Rev 3.0
MOTOROLA