STAX Rp (only BC or DE) in 8085 in microprocessor STA Address (16b) instruction in 8085 ?
STA Address (16b)
Description – the contents of the accumulator are stored at the memory location specified.
Bytes/M-cycles/T-States 3/4/13
Hex code 32
Flags no flags are affected.
STAX Rp (only BC or DE)
Description – the contents of the accumulator are stored at the memory location pointed to by the register pair. The contents of the accumulator are not affected.
Bytes /M-Cycles /T-States 1/2/7
Register pair
Hex codes 02 BC
12 DE
Flags no flags are affected.
STC
Description the carry flag CY is set to 1.
Bytes /M-Cycles/T-States 1/1/4
Hex Code 37
Flags only the CY flag is affected.
SUB R
Description the contents of the register are subtracted from the accumulator and the result is stored in the accumulator.
Bytes/M-Cycles/T-States 1/1/4
Register
Hex codes 97 A
90 B
91 C
92 D
93 F
94 H
95 L
Flags all flags are affected by the result of the operation.
SUB M
Description the contents of the memory location pointed to by HL are subtracted from the accumulator and the result is stored in the accumulator.
Bytes/M-Cycles/T-States 1/2/7
Hex code 96
Flags all flags are affected by the result of the operation.
SUI data (8b)
Description the 8-bit data is subtracted from the contents of the accumulator. The result is stored in the accumulator.
Bytes /M-Cycles/T-States 2/2/7
Hex code D6
Flags all flags are affected by the result of the operation.
XCHG
Description the contents of register H and register D are exchanged, and the contents of register L and register E are exchanged.
Bytes/M-Cycles/T-States 1/1/4
Hex code EB
Flags no flags are affected.
XRA R
Description the contents of the register are exclusive-ORed with the contents of the accumulator. The results are then stored in the accumulator.
Bytes/M-Cycles/T-States 1/1/4
Register
Hex codes AF A
A8 B
A9 C
AA D
AB E
AC H
AD L
Flags Z, S, and P are affected based upon the operation. CY and AC are reset.
XRA M
Description the contents of the memory location pointed to by HL are Exclusive-ORed with the contents of the accumulator. The results are stored in the accumulator.
Bytes/M-Cycles/T-States 1/2/7
Hex code AE
Flags Z, S and P are affected based upon the operation. CY and AC are reset.
XRI Data (8b)
Description the 8 bits of data are exclusive-ORed with the contents of the accumulator. The results are then stored in the accumulator.
Bytes/M-Cycles/T-States 2/2/7
Hex code EE
Flags Z, S and P are affected based upon the operation CY and AC are reset.
XTHL
Description the contents of the L register are exchanged with the stack location pointed to by the stack pointer. The contents of the H register are exchanged with the stack location pointed to by the stack pointer + 1. The stack pointer remains unchanged.
Bytes/M-Cycles/T-States 1/5/16
Hex code E3
Flags no flags are affected.
- Interrupts in 8085
Interrupts type instructions hardware trigger vector
TRAP non-maskable independent of EI no external level and edge 0024H
And DI hardware sensitive
RST 7.5 maskable controlled by EI and DI no external edge-sensitive 003CH
Hardware
RST 6.5 maskable controlled by EI and DI no external level sensitive 0034H
Hardware
RST 5.5 maskable controlled by EI and DI no external level sensitive 002CH
Hardware
INTR 8085 maskable controlled by EI and DI RST code from level sensitive 038H
External hardware |
0000H
Instruction Summary
Data Transfer Instructions
MOV – Copy from source to destination
MVI – move immediate 8-bit
LDA – Load accumulator
LDAX – Load accumulator indirect
LXI – Load register pair immediate
LHLD – Load H and L registers direct
STA – Store accumulator direct
STAX – Store accumulator indirect
XCHG – Exchange H and L with D and E
SPHL – Copy H and L registers to the stack pointer
XTHL – Exchange H and L with top of stack
PUSH – Push register pair onto stack
POP – Pop of stack of register pair
OUT – output data from accumulator to a port with 8-bit address
IN – Input data to accumulator from a port with 8-bit address
Arithmetic Instructions
ADD – Add register or memory to accumulator
ADC – Add register to accumulator with carry
ADI – Add immediate to accumulator
ACI – Add immediate to accumulator with carry
DAD – Add register pair to H and L registers
SUB – Subtract register or memory from accumulator
SBB – Subtract source and borrow from accumulator
SUI – Subtract immediate from accumulator
SBI – Subtract immediate from accumulator with borrow
INR – Increment register of memory by 1
INX – Increment register pair by 1
DCR – Decrement register or memory by 1
DCX – Decrement register pair by 1
DAA – Decimal adjust accumulator
Control Instructions
NOP – No operation
HLT – Halt
DI – Disable interrupts
EI – Enable interrupts
RIM – Read interrupt mask
SIM – Set interrupt mask
Branching Instructions
JMP – Jump unconditionally
JC – Jump on carry
JNC – Jump on no carry
JP – Jump on positive
JM – Jump on minus
JZ – Jump on zero
JNZ Jump on no zero
JPE – Jump on parity even
JPO – Jump on parity odd
CALL – Call unconditionally
CC – Call on carry
CNC – Call on no carry
CP – Call on positive
CM – Call on minus
CZ – Call on zero
CNZ – Call on no zero
CPE – Call on parity even
CPO – Call on parity odd
RET – Return unconditionally
RC – Return on carry
RNC – Return on no carry
RP – Return on positive
RM – Return on minus
RZ – Return on zero
RNZ – Return on no zero
RPE – Return on parity even
RPO – Return on parity even
RPO – Return on parity odd
PCHL – Load program counter with HL contents
RST – Restart
Logical Instructions
CMP – Compare register or memory with accumulator
CPI – Compare immediate with accumulator
ANA – Logical AND register or memory with accumulator
ANI – Logical AND immediate with accumulator
XRA – Exclusive – OR register or memory with accumulator
ORI – Logical OR immediate with accumulator
RLC – Rotate accumulator left
RRC – Rotate accumulator right
RAL – Rotate accumulator left through carry
RAR – Rotate accumulator right through carry
CMA – Complement accumulator
CC – Complement carry
STC – Set carry
- 8085 Microprocessor programs
Addition of two 8-bit number program
MVI – C,00 Initialize C register to 00
LDA – 4150 Load the value to accumulator
MOV B,A – Move the content of accumulator to B register
LDA – 4151 Load the value to accumulator
ADD – B – Add the value of register B to A
JNC –LOOP Jump on no carry
INR – C Increment value of register C
LOOP: STA – 4152 – Store the value of accumulator (sum).
MOV – A,C – Move content of register C to accumulator
STA – 4153 Store the value of accumulator (carry)
HLT – Halt the program
Observation
Input : 80 (4150)
80 (4251)
Output : 00 (4152)
01 (4153)
Subtraction of two 8-bit numbers program
MVI – C,00 Initialize C to 00
LDA – 4150 Load the value to accumulater
MOV – B,A Move the content of accumulator to B register
LDA – 4151 Load the value to accumulator
SUB – B
JNC – LOOP Jump on no carry
CMA – Complement accumulator contents
INR – A Increment value in accumulator
INR – C Increment value in register C
LOOP: STA – 4152 Store the value of A register to memory address
MOV – A,C Move contents of register C to accumulator
STA – 4153 Store the value of accumulator memory address
HLT – Terminate the program
Observation
Input : 06 (4150)
02 (4251)
Output: 04 (4152)
01 (4143)
Multiplication of two 8-bit numbers
Program
MVI – D,00 Initialize register D to 00
MVI – A, 00 Initialize accumulator content to 00
LXI , 4150
MOV – B,M Get the first number in B register
INX – H
MOV – C,M Get the second number in C register
LOOP : ADD – B add content of A register to register B
JNC – NEXT – Jump on no carry to next
INR – D Increment content of register D
NEXT : DCR C decrement content of register C
JNZ – LOOP jump on no zero to address
STA – 4152 – Store the result in memory
MOV – A,D
STA – 4153 store the MSB of result in memory
HLT – Terminate the program
Observation
Input : FF (4150)
FF (4151)
Output : 01 (4152)
FE (4153)
Division of two 8 bit numbers
Program
LXI – H, 4150
MOV – B,M get the dividend in B register
MVI – C,00 Clear C register for quotient
INX – H
MOV – A,M gat the divisor in A register
NEXT: CMP – B compare A register with register B
JC – LOOP jump on carry to loop
SUB – B subtract A register from B register C
JMP – NEXT – jump to next
LOOP : STA – 4152 store the remainder in memory
MOV – A,C
STA – 4153
HLT – Terminate the program
Observation
Input : FF (4150)
FF (4251)
Output : 01 (4152) (Remainder)
FE (4153) (quotient)
Largest Number in an Array of Data
Program
LXI – H, 4200 set pointer for array
MOV – B,M load the count
INX – H
MOV – A,M set 1 st element as largest data
DCR – B decrement the count
LOOP: INX – H
CMP – M if A register > M, go to ahead
JNC – AHEAD
MOV – A,M set the new value as largest
AHEAD : DCR – B
JNZ – LOOP repeat comparisons till count = 0
STA – 4300 store the largest value at 4300
Observation
Input : 05 (4200)
0A (4201)
F1 (4202)
1F (4203)
26 (4204)
FE (4205)
Output : FE (4300)
Smallest Number in an Array of Data
Program
LXI H, – 4200 set pointer for array
MOV – B,M load the count
INX – H
MOV – A,M set 1st element as largest data
DCR – B decrement the count
LOOP : INX – H
CMP – M if A register < M, go to ahead
JC – AHEAD
MOV – A,M set the new value as smallest
AHEAD : DCR – B
JNZ – LOOP repeat comparisons till count = 0
STA – 4300 store the largest value at 4300
HLT
Observation
Input : 05 (4200)
0A (4201)
F1 (4202)
1F (4203)
26 (4204)
FE (4205)
Output : 0A (4300)
Arrange an Array of Data in Ascending Order
Program
LXI – H,4200
MOV – C,M
DCR – C
REPEA : MOV – D,C
LXI – H,4201
LOOP : MOV – A,M
INX – H
CMP – M
JC – SKIP
MOV – B,M
MOV – M,A
DCX – H
MOV – M,B
INX – H
SKIP : DCR – D
JNZ – LOOP
DCR – C
JNZ – REPEAT
HLT
Observation
Input : 4200 05
4201 05
4202 04
4203 03
4204 02
4205 01
Output : 4200 05
4201 01
4202 02
4203 03
4204 04
4205 05
Arrange an Array of data in Descending Order
Program
LXI – H, 4200
MOV – C,M
DCR – C
REPEAT : MOV – D,C
LXI – H,4201
LOOP : MOV – A,M
INX – H
CMP – M
JNC – SKIP
MOV – B,M
MOV – M,A
DCX – H
MOV – M,B
INX – H
SKIP : DCR – D
JNZ – LOOP
DCR – C
JNZ – REPEAT
HLT
Observation
input : 4200 05 (array size)
4201 01
4202 02
4203 03
4204 04
4205 05
4201 05
4202 04
4203 03
4204 02
4205 01
BCD to Hex Conversion
Program
LXI H,4150
MOV A,M Initialize memory pointer
ADD A MSD X2
MOV B,A Store MSD X2
ADD A MSD X4
ADD A MSD X8
ADD B MSD X 10
INX H Point to LSD
ADD M Add to form hex
INX H
MOV M,A Store the result
HLT
Observation
Input : 4150 : 02
4151 : 09 (MSD)
Output : 4152 : 1D H (LSD)
Hex to BCD Conversion
Program
LXI H,4`150 Initialize memory pointer
MVI D, 00 Clear D register for most significant byte
XRA A Clear accumulator
MOV C,M Get hex data
LOOP2: ADI 01 Count the number one by one
DAA Adjust for BCD count
JNC LOOPI
INR D
LOOP1: DCR C
JNZ LOOP2
STA 4151 store the least significant byte
MOV A,D
STA 4152 Store the most significant byte
HLT
Observation
Input : 4150 : FF
Output : 4151 : 55 (LSB)
4152 : 02 (MSB)
Hex to ASCII Conversion
Program
LDA 4200 Get hexa data
MOV B,A
ANI OF Mask upper nibble
CALL SUBI Get ASCII code for upper nibble
STA 4201
MOV A,B
ANI F0 Mask lower nibble
RLC
RLC
RLC
RLC
CALL SUBI Get ASCII code for lower nibble
STA 4202
HLT
SUBI : CPI 0A
JC SKIP
ADI 07
SKIP : ADI 30
RET
Observation
Input : 4200 E4 (Hexa data)
Output : 4201 34 (ASCII code for 4)
4202 45 (ASCII code for E)
ASCII to hex Conversion
Program
LDA 4500
SUI 30
CPI OA
JC 07
SKIP : STA 4501
HLT
Observation
Input : 4500 31
Output : 4501 0B