8048/804 I FAMILY

CROSS-ASSEMBLER

USERIS MANUAL

XASM48 Assembler Version 1.60

Manual Revision 1.4 <l7-MAR-81>

Copyright ec> 1983. 1984 Avocet Systems. Inc.

All rights reserved.

The name AVOCET and the bird logo are trademarks of Avocet Systems.
CPIM is a trademark of Digital Resear!=h.
MS-DOS Is a trademark of Microsoft Corp.
VEDIT is a trademark of Compuview Products.
WORDSTAR is a trademark of Micropro.

AVOCET SYSTEMS. INC.

804 SOUTH STATE ST.
DOVER. DELAWARE 19901

(302) 734-0151
%ASM48 User's Manual Table ot' Contents

Section 1 Introduction 1

Section 2 Running the Cross-Assembler

2.1 XASM48 Command Strings ••••••••••••••• 3

2.2 XASM48 Switches •••••••••••••••••••••• 3
2.3 Summary of Defaults •••••••••••••••••• 4

Section 3 Syntax ot' Assembler Source Files

3.1 Statements ........................... 5

3.2 Symbols • • • • • • • • • • • • • • • • • • • • • • • • • • • • • • 5
3.3 Numeric Constants •••••••••••••••••••• 5
3.4 Character Constants •••••••••••••••••• 6
3.5 Location-Counter Reference ••••••••••• 6
3.6 Expressions ....................... _. . . 6·
3.61 Arithmetic Operators •••••••••••• 7
3.62 Shift Operators ••••••••••••••••• 7
3.63 ayte-Extraction Operators ••••••• 7
3.64 Boolean Operators ••••••••••••••• 8
3.65 Relational Operators •••••••••••• 8
3.66 Evaluation of Expressions ••••••• 9

Section 4 Instruction Set Idiosyncracies 10

Section 5 Pseudo-Opera.tions

5.1 Storage Definition ••••••••••••••••••• 11·

5.2 ORG and END .......................... 12
5.3 Symbol Definition •••••••••••••••••••• 12
5.4 Conditional Assembly ••••••••••••••••• 13
5.5 Listing Control ••.••••••••••••••••••• 14
5.6 External Source Files •••••••••••••••• 15
5. 7 Operator Synonyms ••••• '.' • • • • • • • • • • • • • 15
5.8 Target Machine Validation •••••••••••••• 16

Section 6 Errors .......................... 17

XASM48 User's Manual i'able or Contents, Continued

Section 1 FOrDBt or Listings

1.1 Page Headings •••••••••••.•••••••••••• 18

7.2 Line Headings •••••••••••••••••••••••• 18
1.3 Symbol-Table Listing ••••••••••••••••• 19

Appendix A
Error Messages and Flags A-I
Appendix B
Object File Formats B-1

Appendix C
Summary of Instruction Sets C-l

Appendix D
Instruction Mnemonics and Opcodes ••••••••• D-l
XASM48 User's Manual Page 1

1.0 Introduction

XASM48 is a cross-assembler designed to run on 8080- and

Z80-based microcomputers, under the CP/M* operating system.
It generates machine code ror the Intel 8048 ramily or
microprocessors, accepting standard 8048 mnemonics and
syntax.

The 8048 ramily includes rive dirrerent processor groups, as

distinguished by slightly dirrerent instruction sets; these
are represented by the 8048, 804lA, 8041, 8022, and 8021
chips. Within each group, various models provide a
selection or memory and input/output conrigurations. XASM48
assembles instructions ror all rive groups, and has'
provisions ror rlagging instructions not available in a
speciried target machine.

XASM48 accepts its input rrom a CP/M text rile, and

generates as output an object code rile, an assembly
listing, and an alphabetized listing or all symbols derined
in the assembly. The object rile may be in Intel HEX rormat
or may be omitted altogether, at the user's discretion. The
listings are normally sent to the system's LIST device, but
may be directed to the console or to a disk rile. .

The assembler reatures a variety or pseudo-operations. In

addition to the usual storage-derinition instructions, there
are racilities ror conditional assembly, ror control or
listing rormat, and ror including multiple source riles in
an assembly. New mnemonics may be derined as synonyms ror
existing operations and pseudo-operations, thus eaSing the
task or converting existing programs.

*Trademark or Digital Research.

XASM48 User's Manual. Page 2

This document is intended as a reference manual for the

experienced user. As such, it assumes familiarity with the
8048 instruction set, with the operation of CP/M, and with
assemblers in general. Users lacking this background
information may obtain it from the CP/M manuals and from the
references listed below:

Mcs-48 USER'S MANUAL Intel Corp. No. 9800270

UPI-4l USER'S MANUAL Intel Corp_ No. 9800504

UPI-41A USER'S MANUAL Intel Corp_ No. 9800504-02

Mcs-48 AND UPI-4l

ASSEMBLY LANGUAGE MANUAL Intel Corp_ No. 9800255
XABM48 User's Manual Page 3

2.0 Running tbe Cross-Assembler

2.1 XASM~ ColllllBnd Strings

The 8048 cross-assembler is invoked b,y typing

XASM48 [d:]fi1ename[.ext] [d:] [switches]

The d:'s are optional drive specifiers (eg. A:, B:, etc.).
The file extension (.ext) is also optional; if omitted, it
defaults to .ASM. The second d: specifies a disk dri ve' for
the output files (object and listing);' if it is omitted,
these files are placed on the currently-logged drive. The
switches are (optional) Single characters which control the
output of the assembler, as described below.

2.2 XASM~ Switcbes

The switches following the filename, if supplied, control

various options as follows:

L Listing only; ie. no object file.

X No assembly listing.

Y No symbol-table listing

o Object only; equivalent to XY.

C Send listing, if any, to console instead of LST:

device~

D Send listing, if any, to disk file with same name

as source file and extension "PRN".

N Suppress pagination of assembly listing; ie. no

page headings or pa~e ejects.
XASM48 User's Manual PageIJ

The switches may be used in combination; for example,

XASM48 GRINCH YC
will suppress the symbol-table listing and send the assembly
listing to the console. Note that errors are always listed,
even if listing is turned off. Thus,

XASM48 GRINCH LXYC

will list errors only, on the console.

2.3 Sunma.ry of Defaults

The default output options, in the absence of their

respective specifiers, are as follows:

The source file is assumed to have ext"ension "ASM"

and to reside on the currently-logged drive.

An object file is generated. It is in Intel HEX

format and is placed on the currently-logged
drive.

An assembly listing and a symbol-table listing are

generated; they are sent to the CP/M 1ST: device.
XASM1W3 User' 8 Manual Page 5

3.0 Syntax of' Assembler Source Files

3.1 Statements
Source files consist of a sequence of statements of one o:f
the forms:

[label: ] operator [arguments] [;comment]

symbol operator [arguments] [;comment]

[;comment]

If a label or a leading symbol is present, it must begin in

column 1. Labels must be followed by a colon. Blank lines
are treated as comments. Elements of a statement may be
separated by blanks or tabs.

3.2 §ymbols

Symbols may be up to 8 characters in length, and may include

any of the following characters:
A •• Z 0 •• 9 $

The first character of a .symbol must be a letter or a period.

3 • 3 lIumeric Constants
Numeric constants consist of a sequence of digits,
optionally preceeded or followed by a radix specifier. The
first character must be either a leading radix specifier or
a decimal digit (0 .. 9). The de:fault. radix is ten. For
compatiblity with existing assemblers, other bases may be
denoted by either a leading or a trailing specifier. The
leading radix specifiers are:

% (binary) @ (octal) $ (hex)

The trailing specifiers are:

B, (binary) Q (octal) H (hex)

XASM48 User' s Manual Page 6

Thus, for example, the following are equivalent:

%1111111 1111111B @177 177Q $7F 7FH

3.4 Character Constants

Character constants may be used wherever a numeric value is
allowed. A character constant consists of one or two
characters enclosed in single or double quotes (' or ").
The single quote may be used as a character between double
quotes, and vice-versa.
Thus, the following are equivalent:
'A' "A" and 4·1H

'AB' "AB" and 4l42H

3.5 Location-Counter Reference

The character "$" may be used as an element in expressions.
Its value is the value of the location counter at the
beginning of the current statement.

3.6 Expressions
Arithmetic expressions are composed of symbols, numeric
constants, character constants, and operators. All operators
except +, -, *, and / must be separated from their operands
by at least one space. Symbols which are operators are
reserved, and may not be redefined as user symbols.
A description of the operators follows:
XASM~ User's Manual Page 7

3.61 Arithmetic Operators

These treat their operands as l6-bi t unsigned quanti ties,

and return l6-bit results. No overflow checking is
performed.

+ and - Sum and Difference. Operands and results

may be thought of as unsigned or as twos-
complement quantities.

unary + +x is defined as O+x

unary - -x is defined as O-x

*/ . Product and Quotient (unsigned)

MOD Remainder;
x MOD y gives the remainder of x/y

3.62 Shift Operators

SHL Binary left shift. x SHL y yields x shifted
left y places (ie. x multiplied by 2**y).

SHR Binary right shift, logical. x SHR y yields

x shifted right y places (ie. x divided by
2**y) •

If the right argument is negative, then the direction of the

shift is reversed.

3.63 Byte-Extraction Operators

HIGH Returns the value of the most significant byte of

its argument.

LOW Returns the value of the least significant byte

of its argument

These are unary operators, taking an argument on the right.

For example: HIGH l122H is llH, and LOW 1122H is 22H.
XASM48 User's Manual PageS

3.64 Boolean Operators

NOT Unary logical negation. Complements all the bits
in its argument.

AND Logical product; ie. each bit of the result is

obtained by ANDing together the corresponding
bits in the arguments.

OR Logical sum.

XOR Exclusive-OR.

These are all bitwise operators; that is, the same operation
is performed on each operand bit position, with no carry
from one bit position to the next.

For example: NOT 0 is OFFFFH

IOIB AND OIOB is 0
IOIB OR OIOB is IIIB
IOIB XOR OIOB is IIIB
IOIB XOR IOOB is OOIB

3.65 Relational Operators

These perform unsigned 16-bit comparisons of their operands,
returning I for TRUE and 0 for FALSE.

For comparison x R y, where R is a relational operator, the

results are as follows:

EQ TRUE iff x and yare equal

NE TRUE iff x and y are not equal
LE TRUE iff x is less than or equal to y
LT TRUE iff x is strictly less than y
GE TRUE iff x is greater than or equal to y
GT TRUE iff x is strictly greater than y.
XASMlI8 User's Manual Page 9

3.66 Evaluation o~ Expressions

Parentheses may be used to specify the order of evaluation

of subexpressions. In the absence of parentheses, this
order is determined by operator precedence; higher-
precedence operators are evaluated first. In the case of
operators with equal precedence, evaluation proceeds from
left to right. The operators are listed below in groups
according to precedence. Operators in the same horizontal
group have the same precedence:

unary +, unary - (HIGHEST PRECEDENCE)

HIGH LOW

.* / MOD SHR SHL

+ -

EQ NE LT LE GT GE

NOT
AND

OR XOR (LOWEST PRECEDENCE)

XASM48 User' s Manue.l. Page 10

4.0 Instruction Set Idiosyncracies

While the 8048 family instruction set is not discussed in

detail in this manual, some peculiarities of' the jump and
call instructions are worthy of' note:

The 3MP and CALL instructions in machine code contain a

target address of' 11 bits; a 12th bit is supplied via the
memory bank selection f'eature. In the assembler, l2-blt.
addresses are accepted as operands f'or these instructions,
but the high-order bit is. discarded. Range checking is
perf'ormed to ascertain that the target address is less than
or equal to 4095.

No 3MP instruction may begin at location 2047 or at 4095.

No CALL instruction may begin at 2046, 2047, 4094, or 4095.

The short jump instructions (including D3NZ) contain a

single byte operand representing an address within the
current 256-byte page. The assembler accepts addresses in
the range 0•. 4095 as operands f'orthese instructions. Bits
8 thru 11 are discarded when assembling the instruction, but
are compared with the corresponding bits of' the location
counter to make sure the target address is accessible. If' a
short jump begins at the last location of a page (ie. low
order address byte is 255) then its operand must lie in the
f'ollowing page; this is enf'orced by the assembler.
XASMlJ8 User's :Manual Page 11

5.0 Pseudo-Opera.tions

5.1 storage Definition

DB arg[,arg ••• ]

Define ~es. Each arg may be either an expression or

a string. Expressions must evaluate to 8-bit values
(high byte either 0 or 255). Strings may be delimited
by single or double quotes, as for character constants.

For each expression, a single byte of storage is

reserved; initialized to the low byte of the
expression's value. For each string, the characters of
the string are stored in sequential reserved bytes.

If a compound expression beginning with a character

constant is used in a DB, then the expression must be
enclosed in parentheses to keep it from being
incorrectly parsed as a string. For example,
DB ('A'+l)

will give the expected result, while

DB 'A '+1

would be in error.

DW expression[,expression ••• ]

Each expression reserves one word (2 bytes),

initialized to the value of the expression. The value
is placed in memory with the high-order byte first.

m expression

Reserves n bytes, where n is the value of the

expression. The bytes are not initialized.
XASM48 User's Manual Page 12

ORG expression

Set program origin. This statement should precede the

first code-generating statement in the source file. It
sets the program counter initial value to the value of
the expression, thus setting the location of code which
follows. Additional ORG statements may be used to
generate program segments which will load at different
locations.

END [expression]

The last statement of the source file must be an END

statement. An optional argument is allowed; if this is
supplied, its value becomes the start address specified
in the last record of the HEX object file.

5.3 Symbol Definition

EQU and SET

These take the form:

symbol EQU expression

symbol SET expression

They cause the symbol to be defined and given the value

of the argument expression. Symbols defined with EQU
serve as symbolic constants, and may not have their
values changed. Symbols defined with SET are treated
as variables; their values may be changed by additional
SET's.
XASM48 User's Manual Page 13

5.4 Conditional Assembly

IF s ELSE s and END!F

The construct

IF expression
statement

ENDIF

behaves as follows: If the value of the expression is non-

zero, then the statements between the IF and the ENDIF are
assembled. Otherwise, these statements are ignored.
Similarly ,

IF expression
statement

ELSE
statement

ENDIF

causes the first sequence of statements to be processed if

the expression is TRUE (non-zero), and the second sequence
to be processed otherwise.

Condi tionals may be nested to a depth of 10. The value of

the expression in the IF statement must be known in Pass 1.
XABMII8 User' s Manual Page 14

5.5 Listing Control

PAGE [expression]

If the argument is omitted, then this causes an

immediate page eject (ie. a skip to the top of the next
page). If an argument is supplied and has value n,
then an eject occurs only if there are less than n
lines remaining on the current page.

WIDTH expression

Sets the assumed width of the listing page. The value

of the argument may be between 32 and 132, and defaults
to 132.

PGI.D expression

Sets the number of lines which will be printed on each

page of the listing. Note that the page heading takes
up 7 of these lines. The value of the argument may be
between 8 and 255, and defaults to 58.

fiTIB dtextd

Causes the specified text to become the listing page

title, beginning with the next page header printed.
The delimiter d may be any printing character.

If no TITLE statement is used, then XASM48 supplies a

default title conSisting of the text "SOURCE FILE
NAME: " followed by the name and extension of' the input
file.

Sm'TL dtextd

Just like TITLE, but sets the listing page subtitle,

which is printed on the line after the title line.
XASM1J8 User's Manual Page 15

LIST and BOLIST

These allow selective listing o~ portions of a program.

NOLIST turns o~~ the assembly listing, and LIST turns
it back on. I~ listing has been turned o~~ with
NOLIST, then the next LIST encountered will begin a new
page. Command-line switches which disable listing (ie.
X and 0) will take precedence over LIST. NOLIST does
not turn of~ listing o~ the symbol table.

5.6 External Source Piles

INCIlJD d:name.ext

This pseudo-op causes the speci~ied ~ile to be included

as i~ it were present at.this point in the source ~ile.
INCLUD's may not be nested; that is, the ~ile read by
INCLUD may not contain another INCLUD statement. The
~ile must end with an END statement.

5 .7 Operator Syno!JjllJS

The statement

symbol OPSYN operator

causes the given symbol to be de~ined as a synonym ~or the

operator or pseudo-op speci~ied as argument. This is
particularly useful when assembling source files written for
another assembler. For example, i~ a program uses .BYTE
instead o~ DB, it could be correctly assembled by including
the statement
. BYTE OPSIN DB
XASM48 User I s Manua1 Page 16

5.8 Target Machine Validation

XASM48 checks to see that each instruction assembled is in
the target machine's instruction set. The default target
instruction set is that of the 8048. Others may be
specified by one of the foliowing pseudo-ops:
MOD41A
MOD4l
MOD22
MOD2l

Only one of these may appear in a given program; it may only

appear once, and it must precede all code-generating
instructions.

The instruction sets for the five machine groups are listed
in appendices C and D.
XASM8 User I s Manual Page 11

6.0 Errors

Fatal errors result in tbe printing of an error message on

tbe console and immediate return to CP/M. Fatal errors may
be caused by missing source files, inadequate disk space for
output files, or overflow of tbe symbol table or various
internal stacks.
Non-fatal errors are flagged witb a character in tbe first
column of tbe assembly listing. Lines containing errors are
always listed, even if listing is turned off. A count is
maintained of lines containing errors; if the count is non-
zero at tbeend of tbe assembly, it is printed on tbe
console in tbe message:
***** nnn LINES CONTAINED ERRORS *****

Only one error is listed per line; bence, if a line contains

multiple errors some may not be caugbt until successive
assembler runs.

Tbe fatal error messages and non-fatal error flags are

described in Appendix A.
XASMJJ8 User' s Manual. Page 18

7.0 Format!!!.. Listi.ll@

7.1 ~ Beadings

All listings begin with a heading consisting of seven lines:

(blank line)
(blank line)
(assembler name and version)
(blank line)
(title and page number)
(subtitle)
(blank line)

If no title is supplied in the source program, then the

assembler provides a default title consisting of the message
SOURCE FILE NAME:

followed by the name of the input file in the t'orm name. ext.
The page number is listed at the right-hand end ot' this same
line, always within the specified page width.

If no subtitle is supplied, the subtitle line is left blank.

Both title and subtitle will be truncated, if necessary, to
satiSfY page width constraints.

7.2 Line Beadings

Each code-generating line of the listing begins with the
error flag (blank if no error) and the 4-digi t hexadec i mal
value of the location counter as of the start of the line.
This is followed by up to four bytes of generated code, also
in hexadecimal with two digits per byte. Statements which
generate more than ~ bytes will be assembled correctly, but
only the first four bytes are listed. Lines which do not
generate code but which evaluate an operand (such as EQU or
WIDTH) list the operand value in their headers, in place ot'
the location counter.
XASM48 User's Manual Page 19

7.3 Symbol-Table Listing

The symbol-table listing shows all symbols defined in the
current assembly, with their hexadecimal values. Only user-
defined symbols are listed. Symbols are in vertical
columns, sorted alphabetically according to the ASCII
collating sequence. The number of columns is adjusted
automatically to fit in the specified page width. All pages
of the symbol-table listing are automatically subtitled

- - - SYMBOL TABLE ----

Because the sorting scheme "alphabetizes" symbol names even

if they end in numeric characters, the listing order may not
be what you expect. For example~ a typical sequence of
symbols might appear as follows:

8YMl9
8YM2
8YM20
8YM21
8YM3
8YM4
XASM48 User's Manual Page A-I

APPENDIX A. Error Messages and Fl..a.e!

Bon-Fatal Error Flags

C Conditional Err Unmatched IF, ELSE, or ENDIF; or

conditionals nested too deep.
I INCLUD Err File not found, or nested INCLUD's.

J Jump Err A jump or call instruction begins too

near the end of a 2K page. Jumps and
DJNZ may not begin at locations 2047 or
4095~ CALL may not begin at locations
2046, 2047, 4094, or 4095.

L Label Err Label too long. ()8 chars)

M Multiple Defn Symbol already defined.

0 Operator Err Undefined or illegal operator.

P Phase Err Symbol had different value on Pass 2

than on Pass 1.

R Range Err Argument out of bounds, branch out of

range, or illegal register/port number.

S Syntax Err Ill-formed argument or expression.

U Undefined Undefined symbol(s) in operand field".

W Warning Instruction not available on specified

target ms.chine.
 XASM48 User's Manual Page A-2

Fatal Error Messages

SOURCE FILE NOT FOUND The specified source file

doesn't exist.

UNABLE TO CREATE OUTPUT FILE The directory is full on the

disk specifed· for output.

OUTPUT FILE WRITE ERROR The output. disk is full.

EVALUATION STACK FULL An arithmetic expression vas

encountered vhich had too many
levels of parentheses or of
precedence nesting.

SYMBOL TABLE FULL Not enough memory remains to

create a table entry for a
symbol being defined.

_ Bon-Fatal Error Messages

NO ROOM FOR SYMBOL-TABLE SORT Not enough memory is available

to sort the symbol table.
Symbol-table listing is
therefore omitted.

END STATEMENT MISSING End-of-File vas reached in the

source file~ or in an include
file, vithout encountering an
END statement. The assembler
inserts an END statement,
flagged Qy a string of asterisks
in the comment field.
XABM48 User's Manual Page B-1

APPDDIX B. Object File Format

Object files are in the Intel HEX format, which represents binary
data bytes as two-digit ASCII hexadecimal numbers. An object
file consists of a sequence of data records, followed by a single
end record.

The record formats are:

Data Record:

Byte 1 Colon (:)

2 •• 3 Number of binary data bytes in this record.
4 •• 5 Load address for this record, high byte.
6 •• 7 LOad address, ' , , , ,, low byte.
8 •. 9 Unused, should be "00".
10 •• x Data bytes, two characters each.
x+l. .x+2 Checksum (2 characters).
x+3 •• x+4 CR/LF

End Record:

Like data record, but number of data bytes is zero and the
load address field contains the program starting address.

The checksum is the two's complement of the 8-bit sum,

without carry, of all the data bytes, the two bytes of load
address, and the byte count.
XASM48 User I s Manual Page C-1

.APPEBDIX C. Su:mary Of' Instruction Sets

Mnemonic 8048 804lA 8041 8022 8021

------------
ADD A,#data X X X X X

ADD A,Rr (r=0 •• 7) X X X X X

ADD A,@Rr (r=O .. l) X X X X X

ADDC A,#data X X X X X

ADDC A,Rr (r=0 •• 7 ) X X X X X

ADDC A,@Rr (r=O •• l) X X X X X

ANL A,#data X X X X X

ANL A,Rr (r=0 •• 7 ) X X X X X

ANL A,@Rr (r=O •• l) X X X X X

ANL BUS,#data X

ANL pp,#data (p=l. .2) X X X

ANLD pp,A (p=4 •• 7 ) X X X X X

CALL addr X X X X X

CLR A X X X X X

CLR C X X X X X

CLR FO X X X

CLR F1 X X X

CPL A X X X X X

CPL C X X X X X

CPL FO X X X

CPL F1 X X X

DA A X X X X X
XASM48 User's Manual Page C-2

Mnemonic 8048 804lA 8041 8022 8021

-------------
DEC A X X X X X

DEC Rr (r=O .• 7) X X X

DIS I X X X X

DIS TCNTI X X X X

DJNZ Rr,addr (r=O •• 7) X X X X X

EN DMA X

EN FLAGS X

EN I X X X X

EN T.CNTI X X X X

ENTO CLK X

IN A,DBB X X

IN A,PO X X

IN A,Pp (p=l. .2) X X X X X

INC A X X X X X

INC Rr (r=O •. 7) X X X X X

INC @Rr (r=O •• 1) X X X X X

INS A,BUS X

JBb addr (b=0 .. 7) X X X

JC addr X X X X X

JFO addr X X X

JFl addr X X X

JMp addr X X X X X

JMPP @A X X X X X

JNC addr X X X X X
XASM48 User's Manual Page C-3

Mnemonic 8048 8041A 8041 8022 8021

-------------
JNI addr X

JNIBF addr X X

JNTO addr X X X X

JNT1 addr X X X X X

JNZ addr X X X X X

JOBF addr X X

JTF addr X X X X X

JTO addr X X X X

JT1 addr X X X X X

JZ addr X X· X X X

MOV A,#data X X X X X

MOV A,PSW X X X

MOV A,Rr (r=O •• 7) X X X X X

MOV A,@Rr (r=O •. 1) X X X X X

MOV A,T X X X X X

MOV PSW,A X X X

MOV Rr,A (r=O .• 7) X X X X X

MOV Rr,#data (r=O •. 7) X X X X X

MOV @Rr,A (r=O •• 1) X X X X X

MOV @Rr,#data (r=O •• l) X X X X X

MOV STS,A X

MOV T,A X X X X X

MOVD A,Pp (p=4 •• 7) X X X X X

MOVD Pp,A (p=4 •• 7) X X X X X

XASM48 User's Manual Page c-4

Mnemonic 8048 8041A 8041 8022 8021

------------
MOVP A,@A X X X X X

MOVP3 A,@A X X X

MOVX A,@Rr (r=O •. 1) X

MOVX @Rr,A (r=0 •• 1) X

NOP X X X X X

ORL A,#data X X X X X

ORL A,Rr (r=O •• 7) X X X X X

ORL A,@Rr (r=O .. 1) X X X X X

ORL BUS,#data X

ORL pp,#data (p=1. .2) X X X

ORLD Pp,A (P=4 •• 7) X X X X X

OUT DBB,A X X

OUTL BUS ,A X

OUTL PO,A ·X X

OUTL Pp,A (p=1. .2) X X X X X

HAD X

RET X X X X 'X

RETI X

RETR X X X

RL A X X X X X

RLC A X X X X X

RR A X X X X X

RRC A X X X X X

SEL ANO X
XASM48 User's Manual Page C-5

Mnemonic 8048 8041A 8041 8022 8021

------------
SEL ANI X

SEL MBO X

SEL MB1 X

SEL ROO X X X

SEL RBI X X X

STOP TCNT X X X X X

STRT CNT X X X X X

STRT T X X X X X

SWAP A X X X X X

XCH A,Rr (r=O •• 7) X X X X X

XCH A,@Rr (r=O •• 1) X X X X X

XCHD A,@Rr (r=O •• 1) X X X X X

XRL A,#data X X X X X

XRL A,Rr (r=O •• 7) X X X X X

XRL A,@Rr (r=O •• 1) X X X X X

l.ASM48 User's Manual Page Jrl

APPDDIX D. Instruction Mnemonics and Opcodes

This is an excerpt from an actual XABM48 assembly listing,

showing all of the instruction mnemonics, the available
addressing modes for each, and the associated bex opcodes.
Instructions not available on tbe 8048 proper have been flagged
as "WI! errors by tbe assembler.

0100 ORG 100H

0005 GRINCH EQU 5
0100 68 ADD A,RO
0101 69 ADD A,R1
0102 6A ADD A,R2
0103 6B ADD A,R3
0104 6c ADD A,R4
0105 6D ADD A,R5
0106 6E ADD A,R6
0107 6F ADD A,R7
0108 60 ADD A,@RO
0109 61 ADD A,@R1
010A 0305 ADD A,#GRINCH
010C 78 ADDC A,RO
·010D 79 ADDC A,R1
010E 7A ADDC A,R2
010F 7B ADDC A,R3
0110 7C ADDC A,R4
0111 7D ADDC A,R5
0112 7E ADDC A,R6
0113 7F ADDC A,R7
0114 70 ADDC A,@RO
0115 71 ADDC A,@R1
0116 1305 ADDC A,#GRINCH
0118 58 ANL A,RO
0119 59 ANL A,R1
01lA 5A ANL A,R2
011B 5B ANL A,R3
011C 5C ANL A,R4
01lD 5D ANL A,R5
01lE 5E ANL A,R6
011F 5F ANL A,R7
XABM48 User's Manual Page D-2

0120 50 ANt A,@RO

0121 51 ANt A,@R1

0122 5305 ANL A,#GRINCH

0124 9817 ANt BUS,#17H ;8048 only
0126 9905 ANL P1,#GRINCH ;Not in 8021,8022
0128 9A05 ANL P2,#GRINCH ;Not in 8021,8022
012A 9C ADDR1: ANLD p4,A
012B 9D ANLD P5,A
012C 9E ANLD P6,A
012D 9F ANLD P7,A
012E 342A CALL ADDR1
0130 27 CLR A
0131 97 CLR C
0132 85 CLR FO ;Not in 8021,8022
0133 A5 CLR F1 ;Not in 8021,8022
0134 37 CPL A
0135 A7 CPL C
0136 95 CPL FO ;Not in 8021,8022
0137 B5 CPL F1 ;Not in 8021,8022
0138 57 DA A
0139 07 DEC A

013A C8 DEC RO ;Not in 8021,8022

013B C9 DEC R1 ;Not in 8021,8022
013C CA DEC R2 ;Not in 8021,8022
013D CB DEC R3 ;Not in 8021,8022
013E CC DEC R4 ;Not in 8021,8022
013F CD DEC R5 ;Not in 8021,8022
0140 CE DEC R6 ;Not in 8021",8022
0141 CF DEC R7 ;Not in 8021,8022
0142 15 DIS I ;Not in 8021
0143 35 DIS TeNTI ;Not in 8021
0144 E844 ADDR2: DJNZ RO,ADDR2
0146 E944 DJNZ R1,ADDR2
0148 EA44 DJNZ R2,ADDR2
014A EB44 DJNZ R3,ADDR2
014c Ec44 DJNZ R4,ADDR2
014E ED44 DJNZ R5,ADDR2
0150 EE44 DJNZ R6,ADDR2
0152 EF44 DJNZ R7,ADDR2
XASM48 User' s Manual Page D-3

W0154 E5 EN DMA ;8041A only

W0155 F5 EN FLAGS ;8041A only
0156 05 EN I ;Not in 8021
0157 25 EN TeNTI

0158 75 ENTO CLK ;8048 only

W0159 08 IN A,PO ;8021,8022 only
015A 09 IN A,P1
015B OA IN A,P2
W015C 22 IN A,DBB ;8041/41A only

015D 17 INC A
015E 18 INC RO
015F 19 INC R1
0160 1A INC R2
0161 1B INC R3
0162 1C INC R4
0163 1D INC R5
0164 lE INC R6
0165 IF INC R7
0166 10 INC @RO
0167 11 INC @H1
0168 08 INS A, BUS ;8048 only
0169 1244 JBO ADDR2 ;Not in 8022,8021_
016B 3244 JB1 ADDR2 ;Not in 8022,8021
016D 5244 JB2 ADDR2 ;Not in 8022,8021
016F 7244 JB3 ADDR2 ;Not in 8022,8021
0171 9244 JB4 ADDR2 ;Not in 8022,8021
0173 B244 JB5 ADDR2 ;Not in 8022,8021
0175 D244 JB6 ADDR2 ;Hot in 8022,8021
0177 F244 JB7 ADDR2 ;Hot in 8022,8021
0179 F644 JC ADDR2
017B B644 JFO ADDR2 ;Not in 8022,8021
017D 7644 JFl ADDR2 ;Hot in 8022,8021
017F
017F 242A JMP ADDR1
0181 B3 JMPP @A

0182 E682 ADDR3: JNC ADDR3

0184 8682 JNI ADDR3 ;8048 only
0186 2682 JNTO ADDR3 ;Not in 8021
0188 4682 JNT1 ADDR3
OlBA 9682 JNZ ADDR3
018C 1682 JTF ADDR3
018E 3682 JTO ADDR3 ;Not in 8021
0190 5682 JTl ADDR3
0192 c682 JZ ADDR3
XABM48 User's Manual Page »-4

W0194 D682 JNIBF ADDR3 ;804l/4lA only

W0196 8682 JOBF ADDR3 ;804l/4lA only
0198 237F MOV A,#7FH
019A C7 MOV A,PSW ;Not in 8022,8021
019B F8 MOV A,RO
019C F9 MOV A,Rl
019D FA MOV A,R2
019E FB MOV A,R3
019F FC MOV A,R4
OlAO FD MOV A,R5
OlAl FE MOV A,R6
O1A2 FF MOV A,R7
OlA3 FO MOV A,@RO
OlA4 F1 MOV A,@Rl
OlA5 42 MOV A,T·
OlA6 D7 MOV PSW,A ;Not in 8022,8021
WOlA7 90 MOV STS,A ;804lA only
.OlA8 A8 MOV RO,A
OlA9 A9 MOV Rl,A
OlAA AA MOV R2,A
OlAB AB MOV R3,A
OlAC AC MOV R4,A
OlAD AD MOV R5,A
OlAE AE MOV R6,A
OlAF AF MOV R7,A
OlBO 0005 MOV RO,#GRINCH
01B2 B905 MOV Rl,#GRINCH
01B4 BA05 MOV R2,#GRINCH
01B6 BB05 MOV R3,#GRINCH
OlBa BC05 MOV R4,#GRINCH
OlBA BD05 MOV R5,#GRINCH
OlBC BE05 MOV R6,#GRINCH
OlBE BF05 MOV R7,#GRINCH
OlCO AO MOV @RO,A
OlCl Al MOV @Rl,A
01C2 B005 MOV @RO,#GRINCH
01c4 B105 MOV @Rl,#GRINCH
01c6 62 MOV T,A
01C7 OC MOVD A,p4
01C8 OD MOVD A,P5
01C9 OE MOVD A,P6
OICA OF MOVD A,P7
XASM48 User's Manual Page D-5

OICB 3C MOVD p4,A

01CC 3D MOVD P5,A
01CD 3E MOVD P6,A
01CE 3F MOVD P7,A
01CF A3 MOVP A,@A
0100 E3 MOVP3 A,@.A ;Not in 8022, 8021
OlD180 MOVX A,@RO ;8048 only
OlD2 81 MOVX A,@Rl ;8048 only
OlD3 90 MOVX @RO,A ;8048 only
olD4 91 MOVX @Rl,A ;8048 only
OlD5 00 NOP
olD6 48 ORL A,RO
OlD7 49 ORL A,Rl
OlD8 4A ORL A,R2
OlD9 4B ORL A,R3
OlDA 4c ORL A,R4
OlDB 4D ORL A,R5
OlDC 4E ORL A,R6
OlDD 4F ORL A,R7
OlDE 40 ORL A,@RO
OlDF 41 ORL A,@Rl
OlEO 4305 ORL A,#GRINCH
OlE2 8817 ORL BUS,#17H ;8048 only
OlE4 8907 ORL Pl,#7 ;Not in 8022,8021
OlE6 BA07 ORL P2,#7 ;Not in 8022,8021
OlE8 8C ORLD P4,A
OlE9 8D ORLD P5,A
OlEA 8E ORLD P6,A
OlEB 8F ORLD P7,A
WOlEC 02 OUT DBB,A ;8041/4lA only
OlED 02 OUTL BUS ,A ;8048 only
WOlEE 90 OUTL PO,A ;8021, 8022 only
OlEF 39 OUTL Pl,A
OlFO 3A OUTL P2,A

WOIFI 80 RAD ;8022 only

0lF2 83 RET
WOlF3 93 RETI ;8022 only
olF4 93 RETR ;Not in 8022,8021
XASM48 User's Manual Page D-6

0l.F5 E7 RL A
0lF6 F7 RLC A
01F7 77 RR A
0l.F8 67 RRC A
WOlF9 85 SEL ANO ;8022 only
WOl.FA 95 SEL ANI ;8022 only
OlFB E5 SEL MOO ;8048 only
0l.FC F5 SEL MB1 ;8048 only
OlFD C5 SEL ROO ;Not in 8022,8021
OlFE D5 SEL RBI ;Not in 8022,8021
OIFF 65 STOP TCNT
0200 45 STRT CNT
0201 55 STRT T
0202 47 SWAP A
0203 28 XCH A,RO
0204 29 XCH A,R1
0205 2A XCH A,R2
0206 2B XCH A,R3
0207 2C XCH A,R4
0208 2D XCH A,R5
0209 2E XCH A,R6
020A 2F XCH A,R7
020B 20 XCH A,@RO
020C. 21 XCH A,@Rl
020D 30 XCHD A,@RO
020E 31 XCHD A,@Rl.
020F D8 XRL A,RO
0210 D9 XRL A,Rl
0211 DA XRL A,R2
0212 DB XRL A,R3
0213 DC XRL A,R4
0214 DD XRL A,R5
0215 DE XRL A,R6
0216 DF XRL A,R7
0217 DO XRL A,@RO
0218 Dl XRL A,@Rl
0219 D305 XRL A,#GRINCH
8048 CROSS-ASSEMBLER NOTES (8080/Z80 HOST SYSTEMS) Page 1

Contents Of The Diskette

1. XASM48.eOM ...•.....• 8048/8041 Family Cross-Assembler

2. 'I'EST48 . ASM Demonstration source code file, showing

8048/8041 family instruction set.

Current Versions

Assembler: Vl.64 (Released 04-oct-83)

Manual: Rev. 1.4

Enhancements In Vl.64

1. SYNONYMS FOR PSEUOO-oPS

The pseudo-op EJECT has been added as a synonym for PAGE.

INCLUDE bas been added as a synonym for INeLUD.

2. FORWARD REFERENCES IN PSEUDO-oPS

An 'F' error will occur if a forward reference is present in the

operand of any of the following pseudo-ops:

DS
EQU
IF
LOe
ORG
SET

In general, if an 'F' error is present in your assembly you can expect

obscure problems~ usually, some symbols will have values which don't
correspond to the location counter. Thus, it's best to get rid of all
illegal forward references before trusting the generated code.

3. DEFAULT LISTING DESTINATION

The assembly listing now defaults to a .PRN file, rather than to

the printer. It may be diverted to the printer by specifying the
'P' switch in the assembler command line. The 'D' switch is no
longer recognized.

Bugs Fixed In Vl.64

1. The END statement is now recognized even if an unterminated conditional

(ie. IF without ENDIF) is present.

48README/80 (04-10-84) Copyright (e) 1984, Avocet systems, Inc.

8048 CROSS-ASSEMBLER NOTES (8080/Z80 HOST SYSTEMS) Page 2

2. When the assembly listing is sent directly to the printer, the page
headings no longer contain LF characters with the high-order bit set.

3. The SHR operator has been fixed.

4. Symbols beginning with a period (".") are now accepted.

Known Bugs Remaining In Vl.64

1. The presence of a non-printing ASCII character in a source

line may cause an'S' error, or may cause the line to be
interpreted incorrectly.

2. Quasi-Bug: Assembler input (ie. source file) must be upper-case,

except within quoted strings and character constants.

Updates To XASM48 Manual

1. FORMAT OF OBJECT FILE (Appendix B)

The END record in object files produced by XASM48 is now:

Byte 1
2 •• 3 00 (no. of data bytes)
4 .• 7 0000 (or execution address, if
specified in END statement)
8 •• 9 01 (record type)
10 FF (checksum)

This change reflects Intel's revised definition of the HEX format.

2. RE-DEFINITION OF HARDWARE REGISTERS (VI. 6 3 and Higher)·

By popular request, XASM48 now supports the assignment of symbolic

names to the hardware registers. Thus one can write, for example,

FOO EQU RO
BAR EQU RS

MOV A,@FOO
MOV BAR,#27B

3. INTERRUPTING ASSEMBLY

Assembler operation may be terminated at any time by striking a control-C.

48README/80 (04-10-84) Copyright (C) 1984, Avocet Systems, Inc.

8048 CROSS-ASSEMBLER NOTES (8086/88 HOST SYSTEMS) page 1

Contents Of The Diskette

1. XASM48.CMD (CP/M-86) 8048/8041 Family Cross-Assembler

or
XASM48 . COM (MSDOS)

2. TEST48.ASM Demonstration source code file, showing

8048/8041 family instruction set.

Current Versions

CP/M-86: 1.64C, Released 20-Jul-83

MSDOS (PCDOS): 1.64M, Released 20-Jul-83
Manual: 1.4

Known Bugs in Current Version

1. The presence of a non-printing ASCII character in a source

line may cause an ·S· error, or may cause the line to be
interpreted incorrectly.

2. Forward references are not allowed in ORG, OS, IF, EQU, but
are not flagged as errors if present.

3. Quasi-Bug: ASsembler input (ie. source file) must be upper-case.

Updates To XASM48 Manual (Revision 1.4)

1. ASSEMBLY LISTING DESTINATION (Section 2)

The assembly listing now goes to a .PRN file (not to the printer)
unless otherwise specified. The 'D' switch is no longer recognized.
The 'po switch has been added. It causes the assembly ~isting to
be sent to the printer.

2. FORMAT OF OBJECT FILE (Appendix B)

The END record in object files produced by XASM51 is now:

Byte 1
2 .. 3 00 ( no. of data bytes)
4 .. 7 0000 (or execution address, if
specified in END statement)
8 .. 9 01 (record type)
10 FF ( checksum)

This change reflects Intel's revised definition of the HEX format.

48README/86 (04-10-84) Copyright (C) 1984, Avocet Systems, Inc.

8048 CROSS-ASSEMBLER NOTES (8086/88 HOST SYSTEMS) Page 2

3. RE-DEFINITION OF HARDWARE REGISTERS (General)

By popular request, XASM48 now supports the assignment of symbolic

names to the hardware registers. Thus one can write, for example,

FOO EQU RO
BAA EQU R5

MOV A,@FOO
MOV BAA,#27B

4. INTERRUPTING ASSEMBLY

Assembler operation may be terminated at any time by striking a control-C.

48README/86 (04-10-84) Copyright (C) 1984, Avocet systems, Inc.

8048 Cross-Assembler Notes
==:;:============:========

Contents Of Th~ Diskette

1• X~,SM4S .CeM .......... 8048/8~41 Family Cress-Assembler

2. 1'ES'l'4E, .AStv, Demonstration source code file, showing

8648/8041 family instruction set.

Current Versions

CP/~-fe: 1.64 (REleased 04-Cct-83)

Inharcements In Vi.54

1. SYNCNYMS ]OR PSIUrO-OFS

The pSEudo-or IJECT bas beEP added as a synonym for PAGE.
I~ClUrF has beep added as a synonym fer INCLUD.

2. :F 0 P\I,' APf, RYD h} NC~,S IN F s:n:r:o-oPS

An 'F' errcr will occur if a fcrwerd reference is presEnt in the

operand of anj of tbe following pseudo-ops:
IS
]i:~U
D
LCe
Cf<G
S} l'

In general, if an 'F' error is present in yeur aS5em~li IOU can expert

obscure proble~5; usually, some symbols will have values whicn don 7 t
correspond to the locetion counter. Thus, it's best to bet rid of ell
illegal fcrward references before trusting the generated cede.

z. DEFAULT LISTING LISTI~ATICN

)
The listing now defaults to a .PRN file, rather than to
asse~bly
t~e printer. It may be diverted to the printer by specifying tne
'p' switch in t~e asse~bler co~~and line. The 'D' switch is no
lo~ger recognized.

::tugs Fixed In Vl.f4

1. The END statE"ent is new recognized even if an unterminated conditional

 (iE. IE without ENLU) is present.
? When the assemhly listin~ is sent firE~tly to the printer, the page
headings no lanier contain LF characters with the high-order tit SEt.
~. T~E SER cperater bas been fixed.
4 Sy~to15 tE:~inninf with a peried (".~) are now accepted.

~rcwr lugs PE~airing In Vi.54

1
.1. • The DreserCE of a ror-prirtinf ASCII character in a ~curCf
· p'rn.. a.; rFl'I'~
1 lD._ ~~·",_e an
'.1 'c:,'
" .e. ro.,
"T",er rra! caUSE t"ne 1·l!1e t ,0 ce
T'

interpreted incorrectly.
Quasi-Pug: Assembler in~ut (ie. source file) must be upper-casp,
~.

<- •
except within quote~ 5trin~s and Character constants.

~ates To XASM48 Manual

1. I'OE~Arj OF CFJfC1 FlU

i
(ApPEndix 13)
The E~r record in object files produced by IASM48 1s no~:

.EytE 1 .
(no. of data bytes)
(or execution address, if
spFcifif~ in END statE~ent)
(record type)
(checKsurr)

~his ch2rGE reflEcts IrtEl's reviSEd definition of the 2EX forrrat.

2. F]-IIFI~ITIO~ OF HARD~AR} E]GISTIF~ (Vi.53 and Higher)

By popular re4uEst, XASM~8 row supports the assi~nmEnt cf sYffibclic
names to tne hardware re~ister5. Thus one can write, for example,
ICC HZ
lAF. R5
('10 V P,!5IOO
,":CV BP, R ,#27H

Assembler operation ~ay bE terminated at any time by stri D~ a control-C.