19
Z08617 NMOS Z8
®
8-B
IT
MCU
K
EYBOARD
C
ONTROLLER
INSTRUCTION SET NOTATION
Addressing Modes.
The following notation is used to
describe the addressing modes and instruction opera-
tions as shown in the instruction summary.
Symbol
Meaning
IRR
Indirect register pair or indirect work-
ing-
register pair address
Irr
Indirect working-register pair only
X
Indexed address
DA
Direct address
RA
Relative address
IM
Immediate
R
Register or working-register address
r
Working-register address only
IR
Indirect-register or indirect
working-register address
Ir
Indirect working-register address only
RR
Register pair or working register pair
address
Symbols.
The following symbols are used in describing
the instruction set.
Symbol
Meaning
dst
Destination location or contents
src
Source location or contents
cc
Condition code
@
Indirect address prefix
SP
Stack Pointer
PC
Program Counter
FLAGS
Flag register (Control Register 252)
RP
Register Pointer (R253)
IMR
Interrupt mask register (R251)
Flags.
Control register (R252) contains the following six
flags:
Symbol
Meaning
C
Carry flag
Z
Zero flag
S
Sign flag
V
Overflow flag
D
Decimal-adjust flag
H
Half-carry flag
Affected flags are indicated by:
0
Clear to zero
1
Set to one
*
Set to clear according to operation
-
Unaffected
x
Undefined