MC908AZ32ACFUE Datasheet, PDF (319/324 Pages) Freescale Semiconductor, Inc – Microcontrollers

pull — An instruction that copies into the accumulator the contents of a stack RAM location. The stack
RAM address is in the stack pointer.
pullup — A transistor in the output of a logic gate that connects the output to the logic 1 voltage of the
power supply.
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 signal with
a constant frequency.
push — An instruction that copies the contents of the accumulator to the stack RAM. The stack RAM
address is in the stack pointer.
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 contents of
a RAM memory location remain valid until the CPU writes a different value or until power is turned
off.
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. Writing
to a reserved location has no effect. Reading a reserved location returns an unpredictable value.
reset — To force a device to a known condition.
ROM — Read-only memory. A type of memory that can be read but cannot be changed (written). The
contents of ROM must be specified before manufacturing the MCU.
SCI — See "serial communication interface module (SCI)."
serial — Pertaining to sequential transmission over a single line.
serial communications interface module (SCI) — A module in the M68HC08 Family that supports
asynchronous communication.
serial peripheral interface module (SPI) — A module in the M68HC08 Family that supports
synchronous communication.
set — To change a bit from logic 0 to logic 1; opposite of clear.
shift register — A chain of circuits that can retain the logic levels (logic 1 or logic 0) written to them and
that can shift the logic levels to the right or left through adjacent circuits in the chain.
signed — A binary number notation that accommodates both positive and negative numbers. The most
significant bit is used to indicate whether the number is positive or negative, normally logic 0 for
positive and logic 1 for negative. The other seven bits indicate the magnitude of the number.
software — Instructions and data that control the operation of a microcontroller.
MC68HC908AZ32A Data Sheet, Rev. 2
Freescale Semiconductor
319