Intel 80C196NU, Руководство пользователя

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Glossary-7
GLOSSARY
reserved memory A memory location that is reserved for factory use or
for future expansion. Do not use a reserved memory
location except to initialize it with FFH.
sampled inputs All input pins, with the exception of RESET#, are
sampled inputs. The input pin is sampled one state
time before the read buffer is enabled. Sampling
occurs during PH1 (while CLKOUT is low) and
resolves the value (high or low) of the pin before it is
presented to the internal bus. If the pin value changes
during the sample time, the new value may or may not
be recorded during the read.
RESET# is a level-sensitive input. EXTINTx is
normally a sampled input; however, the powerdown
circuitry uses EXTINTx as a level-sensitive input
during powerdown mode.
saturation mode Saturation occurs when the result of two positive
numbers generates a negative sign bit or the result of
two negative numbers generates a positive sign bit.
Saturation mode prevents an underflow or overflow
of the accumulated value.
set The “1” value of a bit or the act of giving it a “1”
value. See also clear.
SFR Special-function register.
SHORT-INTEGER An 8-bit, signed variable with values from –2
7
t2
7
–1.
sign extension A method for converting data to a larger format by
filling the upper bit positions with the value of the
sign. This conversion preserves the positive or
negative value of signed integers.
sink current Current flowing into a device to ground. Always a
positive value.
source current Current flowing out of a device from V
CC
. Always a
negative value.
SP Stack pointer.
special interrupt Any of the three nonmaskable interrupts (unimple-
mented opcode, software trap, or NMI).