Glossary
68HC(9)12DG128 Rev 1.0
412
Glossary
MOTOROLA
binary-coded decimal (BCD)
— A notation that uses 4-bit binary numbers to represent the 10
decimal digits and that retains the same positional structure of a decimal number. For
example,
234 (decimal) = 0010 0011 0100 (BCD)
bit
— A binary digit. A bit has a value of either logic 0 or logic 1.
branch instruction
— An instruction that causes the CPU to continue processing at a memory
location other than the next sequential address.
break module
— The break module allows software to halt program execution at a
programmable point in order to enter a background routine.
breakpoint
— A number written into the break address registers of the break module. When a
number appears on the internal address bus that is the same as the number in the break
address registers, the CPU executes the software interrupt instruction (SWI).
break interrupt
— A software interrupt caused by the appearance on the internal address bus
of the same value that is written in the break address registers.
bus
— A set of wires that transfers logic signals.
bus clock
— See "CPU clock".
byte
— A set of eight bits.
CAN
— See "Motorola scalable CAN."
CCR
— See “condition code register.”
central processor unit (CPU)
— The primary functioning unit of any computer system. The
CPU controls the execution of instructions.
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.