MC68HC12 MOTOROLA [Motorola, Inc], MC68HC12 Datasheet - Page 463

• Manufacturer Part Number: MC68HC12
• Description: The MC68HC912DT128A microcontroller unit (MCU) is a 16-bit device composed of standard on-chip peripherals including a 16-bit central processing unit
• Manufacturer: MOTOROLA [Motorola, Inc]

CGM — See “clock generator module (CGM).”
clear — To change a bit from logic 1 to logic 0; the opposite of set.
clock — A square wave signal used to synchronize events in a computer.
clock generator module (CGM) — The CGM module generates a base clock signal from which
comparator — A device that compares the magnitude of two inputs. A digital comparator defines
computer operating properly module (COP) — A counter module that resets the MCU if
condition code register (CCR) — An 8-bit register in the CPU that contains the interrupt mask
control bit — One bit of a register manipulated by software to control the operation of the
control unit — One of two major units of the CPU. The control unit contains logic functions that
COP — See "computer operating properly module (COP)."
CPU — See “central processor unit (CPU).”
CPU12 — The CPU of the MC68HC12 Family.
CPU clock — Bus clock select bits BCSP and BCSS in the clock select register (CLKSEL)
MC68HC912DT128A — Rev 4.0
MOTOROLA
the system clocks are derived. The CGM may include a crystal oscillator circuit and/or
phase-locked loop (PLL) circuit.
the equality or relative differences between two binary numbers.
allowed to overflow.
bit and five bits that indicate the results of the instruction just executed.
module.
synchronize the machine and direct various operations. The control unit decodes
instructions and generates the internal control signals that perform the requested
operations. The outputs of the control unit drive the execution unit, which contains the
arithmetic logic unit (ALU), CPU registers, and bus interface.
determine which clock drives SYSCLK for the main system, including the CPU and buses.
When EXTALi drives the SYSCLK, the CPU or bus clock frequency (f
EXTALi frequency divided by 2.
Glossary
o
) is equal to the
Technical Data
Glossary
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