.z80 Directive
Format:
.z80
The .z80 directive enables processing of only the z80 specific
mnemonics. HD64180/Z180 mnemonics encountered without the .hd64
directive will be flagged with an error.
The .z80 directive also selects the Z80 specific cycles
count to be output.
.hd64 Directive
Format:
.hd64
The .hd64 directive enables processing of the HD64180/Z180
specific mnemonics not included in the Z80 instruction set.
HD64180/Z180 mnemonics encountered without the .hd64 directive
will be flagged with an error. A synonym of .hd64 is .z180.
The .hd64 directive also selects the HD64180/Z180 specific
cycles count to be output.
.8085 Directive
Format:
.8085
The .8085 directive enables processing of the standard 8085 in-
structions using the z80 style syntax. Extended (unspecified)
8085 instructions will be flagged with an error. Addressing
modes not supported by the 8085 will be flagged with an er-
ror.
The .8085 directive also selects the 8085 specific cycles
count to be output.
.8085x Directive
Format:
.8085x
The .8085x directive enables processing of the standard and ex-
tended 8085 instructions using the z80 style syntax. Addressing
modes not supported by the 8085 will be flagged with an er-
ror.
The .8085x directive also selects the 8085 specific cycles
count to be output.
See the AS8085 appendix for a description of the extended
(unspecified) instructions enabled by the .8085x directive.
.8080 Directive
Format:
.8080
The .8080 directive enables processing of the standard 8080 in-
structions using the z80 style syntax. All non 8080 instruc-
tions will be flagged with an error. Addressing modes not
supported by the 8080 will be flagged with an error.
The .8080 directive also selects the 8080 specific cycles
count to be output.
THE .__.CPU. VARIABLE
The value of the pre-defined symbol '.__.CPU.' corresponds
to the selected processor type. The default value is 0 which
corresponds to the default processor type. The following table
lists the processor types and associated values for the ASZ80
assembler:
Processor Type .__.CPU. Value
-------------- --------------
.z80 0
.hd64 / .z180 1
.8085 2
.8085x 3
.8080 4
The variable '.__.CPU.' is by default defined as local and
will not be output to the created .rel file. The assembler com-
mand line options -g or -a will not cause the local symbol to be
output to the created .rel file.
The assembler .globl directive may be used to change the
the variable type to global causing its definition to be output
to the .rel file. The inclusion of the definition of the vari-
able '.__.CPU.' might be a useful means of validating that
separately assembled files have been compiled for the same pro-
cessor type. The linker will report an error for variables with
multiple non equal definitions.
Z80 REGISTER SET AND CONDITIONS
The following is a complete list of register designations and
condition mnemonics:
byte registers - a,b,c,d,e,h,l,i,r
register pairs - af,af',bc,de,hl
word registers - pc,sp,ix,iy
C - carry bit set
M - sign bit set
NC - carry bit clear
NZ - zero bit clear
P - sign bit clear
PE - parity even
PO - parity odd
Z - zero bit set
Z80 INSTRUCTION SET
The following list specifies the format for each addressing
mode supported by ASZ80:
#data immediate data
byte or word data
n byte value
rg a byte register
a,b,c,d,e,h,l
rp a register pair
bc,de,hl
(hl) implied addressing or
register indirect addressing
(label) direct addressing
offset(ix) indexed addressing with
an offset
label call/jmp/jr label
The terms data, dir, offset, and ext may all be expressions.
Note that not all addressing modes are valid with every in-
struction, refer to the Z80/HD64180/Z180 technical data for
valid modes.
The following tables list all Z80/HD64180/Z180 mnemonics
recognized by the ASZ80 assembler. The designation [] refers to
a required addressing mode argument.
Inherent Instructions
ccf cpd
cpdr cpi
cpir cpl
daa di
ei exx
halt neg
nop reti
retn rla
rlca rld
rra rrca
rrd scf
Implicit Operand Instructions
adc a,[] adc []
add a,[] add []
and a,[] and []
cp a,[] cp []
dec a,[] dec []
inc a,[] inc []
or a,[] or []
rl a,[] rl []
rlc a,[] rlc []
rr a,[] rr []
rrc a,[] rrc []
sbc a,[] sbc []
sla a,[] sla []
sra a,[] sra []
srl a,[] srl []
sub a,[] sub []
xor a,[] xor []
Load Instruction
ld rg,[] ld [],rg
ld (bc),a ld a,(bc)
ld (de),a ld a,(de)
ld (label),a ld a,(label)
ld (label),rp ld rp,(label)
ld i,a ld r,a
ld a,i ld a,r
ld sp,hl ld sp,ix
ld sp,iy ld rp,#data
ldd lddr
ldi ldir
Call/Return Instructions
call C,label ret C
call M,label ret M
call NC,label ret NC
call NZ,label ret NZ
call P,label ret P
call PE,label ret PE
call PO,label ret PO
call Z,label ret Z
call label ret
Jump and Jump to Subroutine Instructions
jp C,label jp M,label
jp NC,label jp NZ,label
jp P,label jp PE,label
jp PO,label jp Z,label
jp (hl) jp (ix)
jp (iy) jp label
djnz label
jr C,label jr NC,label
jr NZ,label jr Z,label
jr label
Bit Manipulation Instructions
bit n,[]
res n,[]
set n,[]
Interrupt Mode and Reset Instructions
im n
im n
im n
rst n
Input and Output Instructions
in a,(n) in rg,(c)
ind indr
ini inir
out (n),a out (c),rg
outd otdr
outi otir
Register Pair Instructions
add hl,rp add ix,rp
add iy,rp
adc hl,rp sbc hl,rp
ex (sp),hl ex (sp),ix
ex (sp),iy
ex de,hl
ex af,af'
push rp pop rp
HD64180/Z180 Specific Instructions
in0 rg,(n)
out0 (n),rg
otdm otdmr
otim otimr
mlt bc mlt de
mlt hl mlt sp
slp
tst a
tstio #data
... Exit the ASxxxx Documentation
... Home Page
Last Updated: September 2023