Glossary
D-6
O
overflow flag (OV) bit:
A status bit that indicates whether or not an arithme-
tic operation has exceeded the capacity of the corresponding register.
P
PC:
Program counter. A register that contains the address of the next
instruction to be fetched.
peripheral bus:
A bus that is used by the CPU to communicate to the DMA
coprocessor, communication ports, and timers.
pipeline:
A method of executing instructions in an assembly-line fashion.
R
RC:
See repeat counter register.
read/write (R/W) pin:
A memory-control signal that indicates the direction
of transfer when communicating to an external device.
register file:
A bank of registers.
repeat-counter (RC) register:
A 32-bit register in the CPU register file that
specifies the number of times to repeat a block of code when performing
a block repeat.
repeat mode:
A zero-overhead method for repeating the execution of a
block of code. Using repeat modes allows time-critical sections of code to
be executed in the shortest possible time.
reset:
A means to bring the CPU to a known state by setting the registers
and control bits to predetermined values and signaling execution to fetch
the reset vector.
reset pin:
A signal that causes the device to reset.
R/W:
See read/write pin.