Last Updated: January 2006
ACKNOWLEDGMENT
Thanks to Shujen Chen for his contribution of the AS1802
cross assembler.
Shujen Chen
DeVry University
Tinley Park, IL
schen at tp dot devry dot edu
1802 REGISTER SET
The following is a list of the 1802 registers used by AS1802:
r0-r15 - 8-bit registers
sp - register r2
pc - register r3
call - register r4
return - register r5
argr - register r6
1802 INSTRUCTION SET
The following tables list all 1802 mnemonics recognized by
the AS1802 assembler. The designation [] refers to a required
addressing mode argument. The following list specifies the
format for each addressing mode supported by AS1802:
#data immediate data
byte or word data
expr expression
Rn register addressing
label branch label
The terms data, expr, and label may be expressions.
Note that not all addressing modes are valid with every in-
struction, refer to the 1802 technical data for valid modes.
1802 Inherent Instructions
adc add and
dis idl irx
ldx ldxa lsdf
lsie lskp lsnf
lsnq lsnz lsq
lsz mark nop
or req ret
rshl rshr sav
sd sdb seq
shl shlc shr
shrc skp sm
smb stxd xor
1802 Short Branch Instructions
b1 label b2 label
b3 label b4 label
bdf label bge label
bl label bm label
bn1 label bn2 label
bn3 label bn4 label
bnf label bnq label
bnz label bpz label
bq label br label
bz label nbr label
1802 Long Branch Instructions
lbdf label lbnf label
lbnq label lbnz label
lbq label lbr label
lbz label nlbr label
1802 Immediate Instructions
adci #data adi #data
ani #data ldi #data
ori #data sdbi #data
sdi #data smbi #data
smi #data xri #data
1802 Register Instructions
dec Rn ghi Rn
glo Rn inc Rn
lda Rn ldn Rn
phi Rn plo Rn
sep Rn sex Rn
str Rn
inp expr
out expr
CDP1802 COSMAC Microprocessor Instruction Set Summary
----------------------------------------------------------------
| |
| |
| RCA |
| |
| 1 88888 000 22222 |
| 11 8 8 0 0 2 2 |
| 1 8 8 0 0 0 2 |
| 1 88888 0 0 0 222 |
| 1 8 8 0 0 0 2 |
| 1 8 8 0 0 2 |
| 111 88888 000 2222222 |
| |
| CDP1802 COSMAC Microprocessor Instruction Set Summary |
| |
| |
| |
| |
|Written by Jonathan Bowen |
| Programming Research Group |
| Oxford University Computing Laboratory |
| 8-11 Keble Road |
| Oxford OX1 3QD |
| England |
| |
| Tel +44-865-273840 |
| |
|Created August 1981 |
|Updated April 1985 |
|Issue 1.3 Copyright (C) J.P.Bowen 1985|
----------------------------------------------------------------
----------------------------------------------------------------
| |
| CDP1802 COSMAC Microprocessor Pinout |
| |
| _________ _________ |
| _| \__/ |_ |
| --> CLOCK |_|1 40|_| Vdd |
| ____ _| |_ ____ |
| --> WAIT |_|2 39|_| XTAL --> |
| _____ _| |_ ______ |
| --> CLEAR |_|3 38|_| DMA IN <-- |
| _| |_ _______ |
| <-- Q |_|4 37|_| DMA OUT <-- |
| _| |_ _________ |
| <-- SC1 |_|5 36|_| INTERRUPT <-- |
| _| |_ ___ |
| <-- SC0 |_|6 35|_| MWR <-- |
| ___ _| |_ |
| <-- MRD |_|7 34|_| TPA --> |
| _| |_ |
| <--> BUS 7 |_|8 33|_| TPB --> |
| _| |_ |
| <--> BUS 6 |_|9 32|_| MA7 --> |
| _| |_ |
| <--> BUS 5 |_|10 1802 31|_| MA6 --> |
| _| |_ |
| <--> BUS 4 |_|11 30|_| MA5 --> |
| _| |_ |
| <--> BUS 3 |_|12 29|_| MA4 --> |
| _| |_ |
| <--> BUS 2 |_|13 28|_| MA3 --> |
| _| |_ |
| <--> BUS 1 |_|14 27|_| MA2 --> |
| _| |_ |
| <--> BUS 0 |_|15 26|_| MA1 --> |
| _| |_ |
| Vcc |_|16 25|_| MA0 --> |
| _| |_ ___ |
| <-- N2 |_|17 24|_| EF1 <-- |
| _| |_ ___ |
| <-- N1 |_|18 23|_| EF2 <-- |
| _| |_ ___ |
| <-- N0 |_|19 22|_| EF3 <-- |
| _| |_ ___ |
| Vss |_|20 21|_| EF4 <-- |
| |______________________| |
| |
| |
----------------------------------------------------------------
----------------------------------------------------------------
|Mnem. |Op|F|Description |Notes |
|------+--+-+----------------------------+---------------------|
|ADC |74|*|Add with Carry |{DF,D}=mx+D+DF |
|ADCI i|7C|*|Add with Carry Immediate |{DF,D}=mp+D+DF,p=p+1 |
|ADD |F4|*|Add |{DF,D}=mx+D |
|ADI i|FC|*|Add Immediate |{DF,D}=mp+D,p=p+1 |
|AND |F2|*|Logical AND |D={mx}&D |
|ANI i|FA|*|Logical AND Immediate |D={mp}&D,p=p+1 |
|B1 a|34|-|Branch if EF1 |If EF1=1 BR else NBR |
|B2 a|35|-|Branch if EF2 |If EF2=1 BR else NBR |
|B3 a|36|-|Branch if EF3 |If EF3=1 BR else NBR |
|B4 a|37|-|Branch if EF4 |If EF4=1 BR else NBR |
|BDF a|33|-|Branch if DF |If DF=1 BR else NBR |
|BGE a|33|-|Branch if Greater or Equal |See BDF |
|BL a|38|-|Branch if Less |See BNF BR else NBR |
|BM a|38|-|Branch if Minus |See BNF |
|BN1 a|3C|-|Branch if Not EF1 |If EF1=0 BR else NBR |
|BN2 a|3D|-|Branch if Not EF2 |If EF2=0 BR else NBR |
|BN3 a|3E|-|Branch if Not EF3 |If EF3=0 BR else NBR |
|BN4 a|3F|-|Branch if Not EF4 |If EF4=0 BR else NBR |
|BNF a|38|-|Branch if Not DF |If DF=0 BR else NBR |
|BNQ a|39|-|Branch if Not Q |If Q=0 BR else NBR |
|BNZ a|3A|-|Branch if D Not Zero |If D=1 BR else NBR |
|BPZ a|33|-|Branch if Positive or Zero |See BDF |
|BQ a|31|-|Branch if Q |If Q=1 BR else NBR |
|BR a|30|-|Branch |pl=mp |
|BZ a|32|-|Branch if D Zero |If D=0 BR else NBR |
|DEC r|2N|-|Decrement register N |n=n-1 |
|DIS |71|-|Disable |{X,P}=mx,x=x+1,IE=0 |
|GHI r|9N|-|Get High register N |D=nh |
|GLO r|8N|-|Get Low register N |D=nl |
|IDL |00|-|Idle (wait for DMA or int.) |Bus=m0 |
|INC r|1N|-|Increment register N |n=n+1 |
|INP d|6N|-|Input (N=d+8=9-F) |mx=Bus,D=Bus,Nlines=d|
|IRX |60|-|Increment register X |x=x+1 |
|LBDF a|C3|-|Long Branch if DF |If DF=1 LBR else LNBR|
|LBNF a|C8|-|Long Branch if Not DF |If DF=0 LBR else LNBR|
|LBNQ a|C9|-|Long Branch if Not Q |If Q=0 LBR else LNBR |
|LBNZ a|CA|-|Long Branch if D Not Zero |If D=1 LBR else LNBR |
|LBQ a|C1|-|Long Branch if Q |If Q=1 LBR else LNBR |
|LBR a|C0|-|Long Branch |p=mp |
|LBZ a|C2|-|Long Branch if D Zero |If D=0 LBR else LNBR |
|LDA r|4N|-|Load advance |D=mn,n=n+1 |
|LDI i|F8|-|Load Immediate |D=mp,p=p+1 |
|LDN r|0N|-|Load via N (except N=0) |D=mn |
|LDX |F0|-|Load via X |D=mx |
|LDXA |72|-|Load via X and Advance |D=mx,x=x+1 |
|LSDF |CF|-|Long Skip if DF |If DF=1 LSKP else NOP|
----------------------------------------------------------------
----------------------------------------------------------------
|Mnem. |Op|F|Description |Notes |
|------+--+-+----------------------------+---------------------|
|LSIE |CC|-|Long Skip if IE |If IE=1 LSKP else NOP|
|LSKP |C8|-|Long Skip |See NLBR |
|LSNF |C7|-|Long Skip if Not DF |If DF=0 LSKP else NOP|
|LSNQ |C5|-|Long Skip if Not Q |If Q=0 LSKP else NOP |
|LSNZ |C6|-|Long Skip if D Not Zero |If D=1 LSKP else NOP |
|LSQ |CD|-|Long Skip if Q |If Q=1 LSKP else NOP |
|LSZ |CE|-|Long Skip if D Zero |If D=0 LSKP else NOP |
|MARK |79|-|Push X,P to stack (T={X,P})|m2={X,P},X=P,r2=r2-1 |
|NBR |38|-|No short Branch (see SKP) |p=p+1 |
|NLBR a|C8|-|No Long Branch (see LSKP) |p=p+2 |
|NOP |C4|-|No Operation |Continue |
|OR |F1|*|Logical OR |D={mx}vD |
|ORI i|F9|*|Logical OR Immediate |D={mp}vD,p=p+1 |
|OUT d|6N|-|Output (N=d=1-7) |Bus=mx,x=x+1,Nlines=d|
|PLO r|AN|-|Put Low register N |nl=D |
|PHI r|BN|-|Put High register N |nh=D |
|REQ |7A|-|Reset Q |Q=0 |
|RET |70|-|Return |{X,P}=mx,x=x+1,IE=1 |
|RSHL |7E|*|Ring Shift Left |See SHLC |
|RSHR |76|*|Ring Shift Right |See SHRC |
|SAV |78|-|Save |mx=T |
|SDB |75|*|Subtract D with Borrow |{DF,D}=mx-D-DF |
|SDBI i|7D|*|Subtract D with Borrow Imm. |{DF,D}=mp-D-DF,p=p+1 |
|SD |F5|*|Subtract D |{DF,D}=mx-D |
|SDI i|FD|*|Subtract D Immediate |{DF,D}=mp-D,p=p+1 |
|SEP r|DN|-|Set P |P=N |
|SEQ |7B|-|Set Q |Q=1 |
|SEX r|EN|-|Set X |X=N |
|SHL |FE|*|Shift Left |{DF,D}={DF,D,0}<- |
|SHLC |7E|*|Shift Left with Carry |{DF,D}={DF,D}<- |
|SHR |F6|*|Shift Right |{D,DF}=->{0,D,DF} |
|SHRC |76|*|Shift Right with Carry |{D,DF}=->{D,DF} |
|SKP |38|-|Short Skip |See NBR |
|SMB |77|*|Subtract Memory with Borrow |{DF,D}=D-mx-{~DF} |
|SMBI i|7F|*|Subtract Mem with Borrow Imm|{DF,D}=D-mp-~DF,p=p+1|
|SM |F7|*|Subtract Memory |{DF,D}=D-mx |
|SMI i|FF|*|Subtract Memory Immediate |{DF,D}=D-mp,p=p+1 |
|STR r|5N|-|Store via N |mn=D |
|STXD |73|-|Store via X and Decrement |mx=D,x=x-1 |
|XOR |F3|*|Logical Exclusive OR |D={mx}.D |
|XRI i|FB|*|Logical Exclusive OR Imm. |D={mp}.D,p=p+1 |
| | |-|Interrupt action |T={X,P},P=1,X=2,IE=0 |
|------+--+-+--------------------------------------------------|
| |??| |8-bit hexadecimal opcode |
| |?N| |Opcode with register/device in low 4/3 bits |
| | |-|DF flag unaffected |
| | |*|DF flag affected |
----------------------------------------------------------------
----------------------------------------------------------------
|Arguments | Notes |
|-----------+--------------------------------------------------|
| mn |Register addressing |
| mx |Register-indirect addressing |
| mp |Immediate addressing |
| R( ) |Stack addressing (implied addressing) |
|-----------+--------------------------------------------------|
| D |Data register (accumulator, 8-bit) |
| DF |Data Flag (ALU carry, 1-bit) |
| I |High-order instruction digit (4-bit) |
| IE |Interrupt Enable (1-bit) |
| N |Low-order instruction digit (4-bit) |
| P |Designates Program Counter register (4-bit) |
| Q |Output flip-flop (1-bit) |
| R |1 of 16 scratchpad Registers(16-bit) |
| T |Holds old {X,P} after interrupt (X high, 8-bit) |
| X |Designates Data Pointer register (4-bit) |
|-----------+--------------------------------------------------|
| mn |Memory byte addressed by R(N) |
| mp |Memory byte addressed by R(P) |
| mx |Memory byte addressed by R(X) |
| m? |Memory byte addressed by R(?) |
| n |Short form for R(N) |
| nh |High-order byte of R(N) |
| nl |Low-order byte of R(N) |
| p |Short form for R(P) |
| pl |Low-order byte of R(P) |
| r? |Short form for R(?) |
| x |Short form for R(X) |
|-----------+--------------------------------------------------|
| R(N) |Register specified by N |
| R(P) |Current program counter |
| R(X) |Current data pointer |
| R(?) |Specific register |
----------------------------------------------------------------
----------------------------------------------------------------
|Arguments | Notes |
|-----------+--------------------------------------------------|
| a |Address expression |
| d |Device number (1-7) |
| i |Immediate expression |
| n |Expression |
| r |Register (hex digit or an R followed by hex digit)|
|-----------+--------------------------------------------------|
| + |Arithmetic addition |
| - |Arithmetic subtraction |
| * |Arithmetic multiplication |
| / |Arithmetic division |
| & |Logical AND |
| ~ |Logical NOT |
| v |Logical inclusive OR |
| . |Logical exclusive OR |
| <- |Rotate left |
| -> |Rotate right |
| { } |Combination of operands |
| ? |Hexadecimal digit (0-F) |
| --> |Input pin |
| <-- |Output pin |
| <--> |Input/output pin |
----------------------------------------------------------------
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