Intel 8080 - STC, SUB

STC
SUB
STC sets the Cdrry flag to one. No other flags arc affected.
Opcode
Operand
STC
Operands
arc not permitted '.Ivith the STC instruction.
\0 0
Cycles:
States:
Flags:
o
4
Cy
Chapter 3. Instruction Set
SET CARRY
When u'>ed in combination with the rotate accumulator through the carry flag in'>tructions, STC allows the pro-
gram
to modify individudl bits.
SUBTRACT
The SUB in<,truction subtrac1s one byte of data from the contents of the accumulator. The result is stored in the
accullluLltor. SUB u'>('s two"> complement representation of data as explained in Chapter 2. Notice that the SUB
ill'>tructioll
excludes the Cdrrv flag (actually a 'borrow' flag for the purposes of subtraction) but sets the flag to
indicate the
outcome of the :>peration.
Subtract Register from Accumulator
Opcode Operand
SUB
reg
The operands mu,t specifY O;le of the registers A through E, H or L. The imtruction subtr.lcts the contents of
the '>pecified regi,ter from the contents of the accumuldtor using two\ complement data representation. The
re'>ult is stored in the accumulator.
o 0
o S ~
Cycles:
States: 4
Addressing: register
Flag.,:
Z
,S ,P ,CY ,AC
Subtract Memory from Accumulator
Opcode Operand
SU8
M
3-63