intel's mcs-51 family of microcontrollers and its ... viz 8085, z-80, 6502, ... 8c0d 7e mov a,m...

SEVEN SEGMENT DISPLAY INTERFACE

1

CONTENTS

PAGE NO

1.0 Introduction 2

2.0 Description of the Circuit 2

3.0 Installation 4

4.0 Demonstration Examples 5

4.1 Demonstration Program for MPS 85-3 Trainer 5

4.2 Demonstration Program for ESA 85-2 Trainer 6

4.3 Demonstration Program for ESA-80 Trainer 7


4.5 Demonstration Program for ESA-68K Trainer 10

4.6 Demonstration Program for ESA 86/88-2 Trainer 11


4.8 Demonstration Program for ESA 68K-2 Trainer 14


4.10 Demonstration Program for ESA 86/88-3 Trainer 17

4.11 Demonstration Program for ESA-51E Trainer 18

4.12 Demonstration Program for ESA 86/88E Trainer 20

5.0 Exercises 21

Appendix A : Component Layout Diagram

Appendix B : Schematic Diagram


2


1.0 INTRODUCTION

Electro Systems Associates Private Limited (ESA) manufactures trainers for most of the popular

microcomputers viz 8085, Z-80, 6502, 8086/8088 and 68000. ESA offers a variety of modules

which can be interfaced to these trainers. These modules can be effectively used for

teaching/training in the laboratories.

The present manual describes one such interface module seven segment display interface. In

many microprocessor controlled instruments, information processed by the microprocessor has

to be displayed on a front panel. The interfacing technique presented here uses four 7-segment

display units, shift registers and only 4 I/O lines - one for control, one for data and the other two for

power supply.

The advantages of this technique are :

a. The hardware is relatively simple.

b. Only four lines including power supply lines are required for interfacing. Thus the

interconnections with the front panel are minimized.

c. Any segment combinations can be displayed, as the coding is done by software.

This manual describes the operation of the circuit and the installation details. Some demonstration

programs and exercises are also presented to illustrate the application of the interface. Component

layout and the schematic diagram is given in Appendix A and Appendix B respectively.

2.0 DESCRIPTION OF THE CIRCUIT

Please refer to the schematic diagram of this interface, (Appendix B). This interface provides a four-

digit 7 segment display driven by the outputs of four cascaded serial- in - parallel- out shift

registers. Data to be displayed is transmitted serially, bit by bit, to the interface over the port line

PB0. Each bit is clocked into the shift registers by providing a common clock through the port line

PC0. Thus, information for all the four digits is provided by 32 bits clocked into the shift registers

serially.

It can be seen from the circuit that the first bit, after 32 clock pulses, is available at H output of the

shift register U4 and thus controls the H segment of the digit D0. The segments controlled by other

bits can be determined similarly.


3

DISPLAY CODES :

Since the outputs of shift registers are connected to the cathode sides of LED segments, low input

must be given to the segments for making them glow and high inputs for making them blank.

Each display has 7 bar segments and a dot (a,b,c,d,e,f,g,h) as shown in figure below. For

displaying any character, its corresponding segments must be given low inputs.

a

f b

g

e c

d . h

Example :

For displaying digit 3 segments a, b, c, d, g must be given low inputs (i.e. 0s) and the rest high

inputs (i.e 1 s) as shown below.

Segment h g f e d c b a

Bit 7 6 5 4 3 2 1 0

Input 1 0 1 1 0 0 0 0

Hex Code B 0

Display codes of some characters are given below in Table 2-1 for reference.

TABLE 2-1

DISPLAY CODES

APPLIED CODE

(HEX)

DISPLAYED

DIGIT

APPLIED CODE

(HEX)

DISPLAYED

DIGIT

C0 0 80 8

F9 1 90 9

A4 2 88 A

B0 3 83 b

99 4 C6 C

92 5 A1 d

82 6 86 E

F8 7 8E F

3.0 INSTALLATION


4

The interface is housed in a plastic enclosure which has a locking mechanism. To open the cover,

push in the locking mechanism with a finger and lift the cover to open.

The interface module has a 26-pin connector at one edge of the card. This is used for connecting the

interface to the trainer with a flat cable connector set. The +5V DC power required by this

interface is drawn from the trainer via the flat cable connector set.

Table 3-1 shows the connector on various trainers to which this interface can be connected. Some

trainers have two connectors and either may be used for connecting this interface. The

demonstration programs presented in this manual assumes that the interface is connected to

connectors shown in column A. If the connector shown in column B is used, then user has to

change the port addresses appropriately. User may refer to the component layout diagrams of

respective ESA trainers to locate the connectors mentioned here.

TABLE-3.1

MICROPROCESSOR

TRAINER

A B

MPS85-3 J2 J1

ESA85-2 J2 J1

ESA-80 J2 J1

ESA-65 P4

ESA-68K P3 P4

ESA 68K-2 J2 J1

ESA 68-2 J1 J6

ESA 196 J1 J2

ESA-31 J2 J1

ESA-51 J10 J7

ESA-51E J5 J3

ESA-86/88-2 J4 J5

ESA-86/88-3 J8 J9

ESA-86/88E J4 J6

4.0 DEMONSTRATION EXAMPLES


5

DESCRIPTION OF DEMO PROGRAMS

The sample program presented here displays the message "ELECTRO-SYS-TEMS" in a rotating

fashion. In other words, It first blanks the display, Then displays "ELEC", then "TRO-", then

"SYS-", and then "TEMS". These groups are displayed one after another with suitable delays.

The program goes on repeating the entire display sequence. This program is written as an infinite

loop, and hence user must press RESET key to recover from it.

4.1 DEMONSTRATION PROGRAM FOR MPS 85-3 TRAINER

; Assume the interface is connected over J2 of the trainer

; The trainer can be in KEYBOARD MODE or SERIAL MODE.

STRING EQU 8C40H

ADDRESS OPCODE LABEL MNEMONIC COMMENTS

8C00 3E 80 MVI A,80H ;Configure 8255

;for mode 0

8C02 D3 43 OUT 43H ;All ports as O/P

8C04 21 40 8C LOOP4: LXI H,STRING ;Start of display codes

8C07 16 05 MVI D,05 ;5 groups

8C09 06 04 LOOP3: MVI B,04 ;4 characters/group

8C0B 0E 08 LOOP2: MVI C,08 ;8 segments/character

8C0D 7E MOV A,M ;Get display code

8C0E 23 INX H ;Increment pointer

8C0F 07 LOOP1: RLC ;Get one data bit

8C10 5F MOV E,A ;and output it.

8C11 D3 41 OUT 41H

8C13 3E 01 MVI A,01

8C15 D3 42 OUT 42H ;Output the clock to

8C17 3D DCR A

8C18 D3 42 OUT 42H ;Shift register

8C1A 7B MOV A,E

8C1B 0D DCR C ;All Bits over?

8C1C C2 0F 8C JNZ LOOP1 ;No, Continue

8C1F 05 DCR B ;All Character over

8C20 C2 0B 8C JNZ LOOP2 ;No, continue

8C23 CD 30 8C CALL DELAY ;Introduce delay

8C26 CD 30 8C CALL DELAY ;Introduce delay

8C29 15 DCR D ;All groups over?

8C2A C2 09 8C JNZ LOOP3 ;No, Continue

8C2D C3 04 8C JMP LOOP4 ;Yes, start from

;beginning


6

8C30 01 FF FF DELAY: LXI B,0FFFFH ;Delay subroutine

8C33 0B DLY1: DCX B

8C34 78 MOV A,B

8C35 B1 ORA C

8C36 C2 33 8C JNZ DLY1

8C39 C9 RET

ORG 8C40H

8C40 FF FF FF FF STRING DB 0FFH,0FFH,0FFH,0FFH

8C44 C6 86 C7 86 DB 0C6H,86H,0C7H,86H

8C48 BF C0 DE 87 DB 0BFH,0C0H,0DEH,87H

8C4C BF 92 91 92 DB 0BFH,92H,91H,92H

8C50 92 C8 86 87 DB 92H,0C8H,86H,87H

4.2 DEMONSTRATION PROGRAM FOR ESA 85-2 TRAINER

; Assume the interface is connected over J2 of the trainer.


STRING EQU 8040H


8000 3E 80 MVI A,80H ;Configure 8255

;for mode 0

8002 D3 43 OUT 43H ;All ports as O/P

8004 21 40 80 LOOP4: LXI H,STRING ;Start of display

;codes

8007 16 05 MVI D,05 ;5 groups

8009 06 04 LOOP3: MVI B,04 ;4 characters/group

800B 0E 08 LOOP2: MVI C,08 ;8 segments/character

800D 7E MOV A,M ;Get display code

800E 23 INX H ;Increment pointer

800F 07 LOOP1: RLC ;Get one data bit

;and output it.

8010 5F MOV E,A

8011 D3 41 OUT 41H

8013 3E 01 MVI A,01

8015 D3 42 OUT 42H ;Output the clock to

8017 3D DCR A

8018 D3 42 OUT 42H ;Shift register

801A 7B MOV A,E

801B 0D DCR C ;All Bits over?

801C C2 0F 80 JNZ LOOP1 ;No, Continue

801F 05 DCR B ;All Character over


7

8020 C2 0B 80 JNZ LOOP2 ;No continue

8023 CD 30 80 CALL DELAY ;Introduce delay


8029 15 DCR D ;All groups over?

802A C2 09 80 JNZ LOOP3 ;No, Continue

802D C3 04 80 JMP LOOP4 ;Yes, start from

;beginning

8030 01 FF FF DELAY: LXI B,0FFFFH ;Delay subroutine

8033 0B DLY1: DCX B

8034 78 MOV A,B

8035 B1 ORA C

8036 C2 33 80 JNZ DLY1

8039 C9 RET

ORG 8040H

8040 FF FF FF FF STRING DB 0FFH,0FFH,0FFH,0FFH

8044 C6 86 C7 86 DB 0C6H,86H,0C7H,86H

8048 BF C0 DE 87 DB 0BFH,0C0H,0DEH,87H

804C BF 92 91 92 DB 0BFH,92H,91H,92H

8050 92 C8 86 87 DB 92H,0C8H,86H,87H

4.3 DEMONSTRATION PROGRAM FOR ESA-80 TRAINER



STRING EQU 8040H


8000 3E 80 LD A,80H ;Configure 8255

;for mode 0

8002 D3 43 OUT (43H),A ;All ports as O/P

8004 21 40 80 LOOP4: LD HL,STRING ;Start of

;display codes

8007 16 05 LD D,05 ;5 groups

8009 06 04 LOOP3: LD B,04 ;4 characters/group

800B 0E 08 LOOP2: LD C,08 ;8 segments/

;character

800D 7E LD A,(HL) ;Get display code

800E 23 INC HL ;Increment pointer

800F 07 LOOP1: RLCA ;Get one data

8010 5F LD E,A

8011 D3 41 OUT (41H),A ;bit and Output it.

8013 3E 01 LD A,01


8

8015 D3 42 OUT (42H),A ;Output the clock to

8017 3D DEC A

8018 D3 42 OUT (42H),A ;Shift register

801A 7B LD A,E

801B 0D DEC C ;All Bits over?

801C C2 0F 80 JP NZ,LOOP1 ;No, Continue

801F 05 DEC B ;All Character over

8020 C2 0B 80 JP NZ,LOOP2 ;No continue



8029 15 DEC D ;All groups over?

802A C2 09 80 JP NZ,LOOP3 ;No, Continue

802D C3 04 80 JP LOOP4 ;Yes, start from

;beginning

8030 01 FF FF DELAY: LD BC,0FFFFH ;Delay subroutine

8033 0B DLY1: DEC BC

8034 78 LD A,B

8035 B1 OR C

8036 C2 33 80 JP NZ,DLY1

8039 C9 RET

8040 FF FF FF FF STRING:DB 0FFH,0FFH,0FFH,0FFH

8044 C6 86 C7 86 DB 0C6H,86H,0C7H,86H


804C BF 92 91 92 DB 0BFH,92H,91H,92H

8050 92 C8 86 87 DB 92H,0C8H,86H,87H




SEG EQU 0E8H

STRING EQU 8048H


8000 75 A0 E8 MOV P2,#SEG ;Configure 8255

;for mode 0

8003 78 03 MOV R0,#03 ;Port A,B as I/P

8005 74 80 MOV A,#80H ;Port C as O/P.

8007 F2 MOVX @R0,A

8008 90 80 48 LOOP4: MOV DPTR,#STRING ;Store string

800B 7B 05 MOV R3,#05H ;contents


9

800D 79 04 LOOP3: MOV R1,#4 ;4 Characters/Group

800F 7A 08 LOOP2: MOV R2,#08H ;8 Segments/

;Character

8011 E4 CLR A ;Get display code

8012 93 MOVC A,@A+DPTR

8013 A3 INC DPTR ;Increment pointer

8014 23 LOOP1: RL A

8015 FC MOV R4,A

8016 78 01 MOV R0,#1

8018 F2 MOVX @R0,A ;Output it.

8019 74 01 MOV A,#01H

801B 78 02 MOV R0,#02

801D F2 MOVX @R0,A ;Output the clock to

801E 14 DEC A

801F F2 MOVX @R0,A ;Shift register

8020 EC MOV A,R4

8021 1A DEC R2 ;All bits over

8022 BA 00 EF CJNE R2,#0,LOOP1 ;No continue

8025 19 DEC R1 ;All characters over

8026 B9 00 E6 CJNE R1,#0,LOOP2 ;No continue

8029 12 80 35 LCALL DELAY ;Introduce

802C 12 80 35 LCALL DELAY ;delay routine

802F 1B DEC R3 ;All groups over

8030 BB 00 DA CJNE R3,#0,LOOP3 ;No, continue

8033 80 D3 SJMP LOOP4 ;Yes, start

;from LOOP4

8035 C0 83 DELAY: PUSH DPH ;Delay subroutine

8037 C0 82 PUSH DPL

8039 90 00 00 MOV DPTR,#0

803C A3 DELAY1: INC DPTR

803D E5 83 MOV A,DPH

803F 45 82 ORL A,DPL

8041 70 F9 JNZ DELAY1

8043 D0 82 POP DPL

8045 D0 83 POP DPH

8047 22 RET

8048 FF FF STRING: DB 0FF,0FF

804A FF FF DB 0FF,0FF

804C C6 86 DB 0C6,86

804E C7 86 DB 0C7,86

8050 BF C0 DB 0BF,0C0

8052 DE 87 DB 0DE,87

8054 BF 92 DB 0BF,92

8056 91 92 DB 91, 92

8058 92 C8 DB 92, 0C8


10

805A 86 87 DB 86, 87

4.5 DEMONSTRATION PROGRAM FOR ESA-68K TRAINER

; Assume the interface is connected over P3 of the trainer.


40600 20 7C 00 START: MOVEA.L #$4064C,A0 ;Point to the

04 06 4C ;Message area

40606 13 FC 00 MOVE.B #$80,$80306 ;Configure

80 00 08 ;8255 for mode 0

03 06 ;All ports output

4060E 30 3C 00 MOVE #04,D0 ;5 groups

04

40612 32 3C 00 NEXTGR: MOVE #03,D1 ;4 Characters

03 ;per group

40616 34 3C 00 NEXTCH: MOVE #07,D2 ;8 Segments

07 ;per character

4061A 16 18 MOVE.B (A0)+,D3 ;Get display

;code.

4061C E3 1B NEXTSEG: ROL.B #01,D3

4061E 13 C3 00 MOVE.B D3,$80302 ;Output a bit

08 03 02 ;from display

;code through

;Port PB0.

40624 13 FC 00 MOVE.B #01,$80304 ;Output clock

01 00 08 ;over PC0

03 04

4062C 13 FC 00 MOVE.B #00,$80304

00 00 08

03 04

40634 51 CA FF DBRA D2,$NEXTSEG ;If all bits

E6 ;are not over

;go for next one

40638 51 C9 FF DBRA D1,$NEXTCH ;If all chara-

DC ;cters are not

;over,go for

;next one.

4063C 26 3C 00 MOVE.L #$50000,D3 ;Introduce

05 00 00 ;delay

40642 53 83 LOOP: SUBQ.L #01,D3

40644 66 FC BNE $LOOP

40646 51 C8 FF DBRA D0,NEXTGR ;If all groups


11

CA ;are not over,

;go for next

;one.

4064A 60 B4 BRA $START ;Else,go back

;to beginning.

4064C FF FF FF STRING: DC.W $FFFF,$FFFF ;Display codes

FF

C6 86 C7 DC.W $C686,$C786

86

BF C0 DE DC.W $BFC0,$DE87

87

BF 92 91 DC.W $BF92,$9192

92

92 C8 86 DC.W $92C8,$8687

87

4.6 DEMONSTRATION PROGRAM FOR ESA 86/88-2 TRAINER



ORG EQU 00H

CMD55 EQU FFE6H

MODE EQU 80H

STRING EQU 2050H


2000 BA E6 FF MOVW DX,#CMD55 ;Configure 8255

2003 B0 80 MOVB AL,#MODE ;All ports output

2005 EE OUTB DX

2006 BE 50 20 LOOP4: MOVW SI,#STRING ;Start of

;display codes

2009 B1 05 MOVB CL,#05 ;5 groups

200B B5 04 LOOP3: MOVB CH,#04 ;4 characters/group

200D B3 08 LOOP2: MOVB BL,#08 ;8 Segments/

;character

200F 8A 04 MOVB AL,[SI] ;Get the

;display code

2011 46 INCW SI ;Increment pointer

2012 D0 C0 LOOP1: ROLB AL,1 ;Get one data bit

2014 BA E2 FF MOVW DX,#0FFE2

2017 EE OUTB DX ;and Output it.

2018 88 C4 MOVB AH,AL


12

201A B0 01 MOVB AL,#01 ;Output the clock

201C BA E4 FF MOVW DX,#0FFE4

201F EE OUTB DX ;to Shift register

2020 FE C8 DECB AL

2022 EE OUTB DX

2023 88 E0 MOVB AL,AH

2025 FE CB DECB BL ;All Bits over?

2027 75 E9 JNZ LOOP1 ;No, continue

2029 FE CD DECB CH ;All charac-

;ters over?

202B 75 E0 JNZ LOOP2 ;No continue

202D E8 06 00 CALL DELAY ;Introduce delay

2030 FE C9 DECB CL ;All groups over?

2032 75 D7 JNZ LOOP3 ;No continue

2034 EB D0 JMP LOOP4 ;Yes. start from

;beginning.

2036 51 DELAY: PUSH CX ;Delay subroutine

2037 B9 FF FF MOV CX,#0FFFF

203A 90 XCHGW AX,AX

203B 90 XCHGW AX,AX

203C 90 XCHGW AX,AX

203D E2 FB LOOP 203AH

203F B9 FF FF MOVW CX,#0FFFF

2042 90 XCHGW AX,AX

2043 90 XCHGW AX,AX

2044 90 XCHGW AX,AX

2045 E2 FB LOOP 2042H

2047 59 POP CX

2048 C3 RET

ORG 2050H

2050 FF FF FF FF STRING:DB 0FFH,0FFH,0FFH,0FFH

2054 C6 86 C7 86 DB 0C6H,86H,0C7H,86H


205C BF 92 91 92 DB 0BFH,92H,91H,92H

2060 92 C8 86 87 DB 92H,0C8H,86H,87H

4.7 DEMONSTRATION PROGRAM FOR ESA 196 TRAINER

;Assume the interface is connected over J1 of the trainer.

;The trainer can be in KEYBOARD MODE or SERIAL MODE.

REG1 EQU 52H

REG2 EQU 60H

REG3 EQU 56H

REG4 EQU 64H


13

REG5 EQU 68H

REG7 EQU 76H

REG9 EQU 80H

REG10 EQU 88H

PORT_A EQU 200H

PORT_B EQU 202H

PORT_C EQU 204H

CMD_PORT EQU 206H

ADDRESS OPCODE LABLE MNEMONIC COMMENTS

8000 B1 80 52 LDB REG1,#80H ;CONFIGURE 8255

8003 C7 01 06 02 STB REG1,CMD_PORT ;IN MODE 0. ALL

8007 52 ;PORTS O/P.

8008 A1 80 80 60 LOOP4: LD REG2,#MSG ;START OF DISPLAY

800C B1 05 56 LDB REG3,#05H ;CODES. 5 GROUPS.

800F B1 04 64 LOOP3: LDB REG4,#04H ;4 CHARACTES/GROUP.

8012 B1 08 68 LOOP2: LDB REG5,#08H ;8 SEGMENTS/CHARACTER.

8015 B2 60 52 LDB REG1,[REG2] ;GET DISPLAY CODE.

8018 07 60 INC REG2 ;INCREMENT POINTER.

801A B0 52 80 LOOP1: LDB REG9,REG1 ;GET ONE DATA BIT

801D 19 01 80 SHLB REG9,#1H ;AND O/P IT.

8020 71 80 52 ANDB REG1,#80H ;ROTATE LEFT.

8023 18 07 52 SHRB REG1,#7H

8026 90 80 52 ORB REG1,REG9

8029 B0 52 76 LDB REG7,REG1

802C C7 01 02 02 STB REG1,PORT_B

8030 52

8031 B1 01 52 LDB REG1,#01H

8034 C7 01 04 02 STB REG1,PORT_C ;O/P THE CLOCK.

8038 52

8039 15 52 DECB REG1

803B C7 01 04 02 STB REG1,PORT_C ;SHIFT REGISTER.

803F 52

8040 B0 76 52 LDB REG1,REG7

8043 15 68 DECB REG5 ;ALL BITS OVER?

8045 D7 D3 JNE LOOP1 ;NO. LOOP BACK.

8047 15 64 DECB REG4 ;ALL CHARACTERS OVER?

8049 D7 C7 BNE LOOP2 ;NO. LOOP BACK.

804B EF 13 00 LCALL DELAY ;CALL DELAY ROUTINE.

804E EF 10 00 LCALL DELAY

8051 EF 0D 00 LCALL DELAY

8054 EF 0A 00 LCALL DELAY

8057 EF 07 00 LCALL DELAY

805A 15 56 DECB REG3 ;ALL GROUPS OVER?


14

805C D7 B1 JNE LOOP3 ;NO. LOOP BACK.

805E E7 A7 FF LJMP LOOP4 ;REPEAT FROM BEGINNING

;LOOP FOR ;EVER.

8061 A1 FF FF 88 DELAY: LD REG10,#0FFFFH ;DELAY SUBROUTINE.

8065 05 88 DLY1: DEC REG10

8067 D7 FC BNE DLY1

8069 F0 RET

8080 ORG 8080H

8080 FF FF FF FF MSG: DCB 0FFH,0FFH,0FFH,0FFH

8084 C6 86 C7 86 DCB 0C6H,86H,0C7H,86H

8088 BF C0 DE 87 DCB 0BFH,0C0H,0DEH,87H

808C BF 92 91 92 DCB 0BFH,92H,91H,92H

8090 92 C8 86 87 DCB 92H,0C8H,86H,87H

4.8 DEMONSTRATION PROGRAM FOR ESA 68K-2 TRAINER


ORG 400400H

PORTB EQU 800013H

PORTC EQU 800019H

PB_CT EQU 80000FH

PB_DI EQU 800007H

PC_DI EQU 800009H

ADDRESS OPCODE LABLE MNEMONICS COMMENTS

400400 13FC 0000 START: MOVE.B #$0,PB_CT ;Initialise

0080 000F ;Port B & C

;as O/P Ports.

400408 13FC 00FF MOVE.B #$FF,PB_DI

0080 0007

400410 13FC 00FF MOVE.B #$FF,PC_DI

0080 0009

400418 207C 0040 LOOP4: MOVEA.L #STRING,A0 ;Start of

0462 ;display codes

40041E 123C 0005 MOVE.B #$05,D1 ;5 Groups

400422 143C 0004 LOOP3: MOVE.B #$04,D2 ;4 Character /

;group

400426 163C 0008 LOOP2: MOVE.B #$08,D3 ;8 segment /

;character

40042A 1018 MOVE.B (A0)+,D0 ;Get display

;code


15

40042C E318 LOOP1: ROL.B #01,D0 ;Get one data

;bit & output

40042E 13C0 0080 MOVE.B D0,PORTB

0013

400434 13FC 0001 MOVE.B #01H,PORTC ;Output the

0080 0019 ;clock to

;shift register

40043C 13FC 0000 MOVE.B #00H,PORTC

0080 0019

400444 5303 SUBQ.B #01H,D3 ;All bits over

400446 66E4 BNE LOOP1 ;No. continue

400448 5302 SUBI.B #01,D2 ;All characters

;over?

40044A 66DA BNE LOOP2 ;No. continue

40044C 6100 0008 BSR DELAY

400450 5301 SUBI.B #01,D1 ;All groups

;over?

400452 66CE BNE LOOP3 ;No. continue

400454 60C2 BRA LOOP4 ;Yes. start

;from beginning

400456 2C3C 0002 DELAY: MOVE.L #$2FFFF,D6 ;Delay routine

FFFF

40045C 5386 DELY: SUBI.L #01,D6

40045E 66FC BNE DELY

400460 4E75 RTS

400462 FF FF FF FF STRING: DC.B FFH,FFH,FFH,FFH

400466 C6 86 C7 86 DC.B C6H,86H,C7H,86H

40046A BF C0 DE 87 DC.B BFH,C0H,DEH,87H

40046E BF 92 91 92 DC.B BFH,92H,91H,92H

400472 92 C8 86 87 DC.B 92H,C8H,86H,87H



;The trainer can be KEYBOARD MODE or SERIAL MODE.


ORG 8000H

8000 75 A0 E8 MOV P2,#E8H ;Configure 8255

8003 78 03 MOV R0,#03H ;for mode 0

8005 74 80 MOV A,#80H ;Port A,B as I/P

8007 F2 MOVX @R0,A ;Port C as O/P



16


800D 79 04 LOOP3: MOV R1,#04H ;4 Characters

800F 7A 08 LOOP2: MOV R2,#08H

8011 E4 CLR A


8013 A3 INC DPTR ;Increment

;pointer

8014 23 LOOP1: RL A

8015 FC MOV R4,A

8016 78 01 MOV R0,#01H

8018 F2 MOVX @R0,A ;Output it

8019 74 01 MOV A,#01H

801B 78 02 MOV R0,#02H

801D F2 MOVX @R0,A ;Output the clock

801E 14 DEC A


8020 EC MOV A,R4


8022 BA 00 EF CJNE R2,#0,LOOP1 ;No, continue

8025 19 DEC R1 ;All characters

;over


8029 12 80 35 LCALL DELAY ;call delay

802C 12 80 35 LCALL DELAY

802F 1B DEC R3 ;All groups over

8030 BB 00 DA CJNE R3,#0,LOOP3 ;No continue

8033 80 D3 SJMP LOOP4 ;Yes start from

;LOOP4

;Delay Subroutine

8035 C0 83 DELAY: PUSH DPH

8037 C0 82 PUSH DPL

8039 90 00 00 MOV DPTR,#0





8043 D0 82 POP DPL

8045 D0 83 POP DPH

8047 22 RET

8048 FF FF FF FF STRING: DB 0FFH,0FFH,0FFH,0FFH

804C C6 86 C7 86 DB C6H,86H,C7H,86H

8050 BF C0 DE 87 DB BFH,C0H,DEH,87H

8054 BF 92 91 92 DB BFH,92H,91H,92H


17

8058 92 C8 86 87 DB 92H,C8H,86H,87H

4.10 DEMONSTRATION PROGRAM FOR ESA 86/88-3 TRAINER


; This program module displays 'ELECTRO SYSTEMS' on the

; interface LEDs with a preset delay.

; The program can be executed in STAND-ALONE MODE or SERIAL

; MODE of operation.

; The program starts at memory location 0:2000H

; Please refer ESA 86/88-3 user's manual for mnemonic syntax

; suitable to trainer

Code Segment :0000H


2000 B8 00 00 MOVW AX,0000H ;Initialise

2003 8E C8 MOVW CS,AX ;Segment Registers

2005 8E D8 MOVW DS,AX

2007 BA E6 FF MOVW DX,FFE6H ;Configure all 8255

200A B0 80 MOVB AL,80H ;ports as output

200C EE OUTB DX,AL

200D BE 00 21 LOOP4: MOVW SI,2100H ;Initialise pointer

2010 B1 05 MOVB CL,05H ;Set Count for 5

;groups,

2012 B5 04 LOOP3: MOVB CH,04H ;4 characters/group

2014 B3 08 LOOP2: MOVB BL,08H ;8 segments/character

2016 8A 04 MOVB AL,[SI] ;Get the display code


2019 D0 C0 LOOP1: ROLB AL,1 ;Get 1 data bit

201B BA E2 FF MOVW DX,0FFE2H

201E EE OUTB DX,AL ;Output bit to port B

201F 8A E0 MOVB AH,AL

2021 B0 01 MOVB AL,01H ;Output Clock to

2023 BA E4 FF MOVW DX,FFE4H ;Shift Register

2026 EE OUTB DX,AL

2027 FE C8 DECB AL

2029 EE OUTB DX,AL

202A 8A C4 MOVB AL,AH

202C FE CB DECB BL ;All bits over ?

202E 75 E9 JNZ LOOP1 ;No, Continue

2030 FE CD DECB CH ;All Characters

;over ?


18

2032 75 E0 JNZ LOOP2 ;No, Continue

2034 E8 06 00 CALL DELAY ;Introduce delay

2037 FE C9 DECB CL ;All groups over

2039 75 D7 JNZ LOOP3 ;No, Continue

203B EB D0 JMP LOOP4 ;Repeat continuously

203D 51 DELAY: PUSH CX ;Delay Subroutine

203E B9 FF FF MOVW CX,0FFFFH

2041 E2 FE LOOP $

2043 B9 FF FF MOVW CX,0FFFFH

2046 E2 FE LOOP $

2048 59 POP CX

2049 C3 RET

2100 ORG 2100H ;Display Codes table

2100 FF FF FF FF DB 0FFH,0FFH,0FFH,0FFH

2104 C6 86 C7 86 DB 0C6H,086H,0C7H,086H


210C BF 92 91 92 DB 0BFH,092H,091H,092H

2110 92 C8 86 87 DB 092H,0C8H,086H,087H

4.11 DEMONSTRATION PROGRAM FOR ESA-51E TRAINER


;The trainer can be in BOARD MODE or SERIAL MODE.


ORG 8000H

8000 75 A0 E8 MOV P2,#E8H ;Configure 8255

8003 78 03 MOV R0,#03H ;ALL ports as

8005 74 80 MOV A,#80H ;O/P

8007 F2 MOVX @R0,A



800D 79 04 LOOP3: MOV R1,#04H ;5 Groups,

800F 7A 08 LOOP2: MOV R2,#08H ;4 Characters

8011 E4 CLR A ;8 segments


8013 A3 INC DPTR ;Increment

;pointer

8014 23 LOOP1: RL A

8015 FC MOV R4,A

8016 78 01 MOV R0,#01H

8018 F2 MOVX @R0,A ;Output it


19

8019 74 01 MOV A,#01H

801B 78 02 MOV R0,#02H

801D F2 MOVX @R0,A ;Output the

;clock

801E 14 DEC A


8020 EC MOV A,R4


8022 BA 00 EF CJNE R2,#0,LOOP1 ;no continue

8025 19 DEC R1 ;All characters

;over?


8029 12 80 35 LCALL DELAY ;call delay

802C 12 80 35 LCALL DELAY

802F 1B DEC R3 ;All groups

;over?

8030 BB 00 DA CJNE R3,#0,LOOP3 ;No continue

8033 80 D3 SJMP LOOP4 ;Yes start

;from LOOP4

;Delay Subroutine

8035 C0 83 DELAY: PUSH DPH

8037 C0 82 PUSH DPL

8039 90 00 00 MOV DPTR,#0





8043 D0 82 POP DPL

8045 D0 83 POP DPH

8047 22 RET

8048 FF FF FF FF STRING: DB 0FFH,0FFH,0FFH,0FFH

804C C6 86 C7 86 DB C6H,86H,C7H,86H

8050 BF C0 DE 87 DB BFH,C0H,DEH,87H

8054 BF 92 91 92 DB BFH,92H,91H,92H

8058 92 C8 86 87 DB 92H,C8H,86H,87H

4.12 DEMONSTRATION PROGRAM FOR ESA 86/88E TRAINER


; This program module displays 'ELECTRO SYSTEMS' on the

; interface LEDs with a preset delay.


20

; The program can be executed in STAND-ALONE MODE or SERIAL

; MODE of operation.

; The program starts at memory location 0:2000H

; Please refer ESA 86/88E user's manual for mnemonic syntax

; suitable to trainer

Code Segment :0000H


2000 B8 00 00 MOVW AX,0000H ;Initialise

2003 8E C8 MOVW CS,AX ;Segment Registers

2005 8E D8 MOVW DS,AX

2007 BA E6 FF MOVW DX,FFE6H ;Configure all 8255

200A B0 80 MOVB AL,80H ;ports as output

200C EE OUTB DX,AL

200D BE 00 21 LOOP4: MOVW SI,2100H ;Initialise pointer

2010 B1 05 MOVB CL,05H ;Set Count for 5

;groups,

2012 B5 04 LOOP3: MOVB CH,04H ;4 characters/group

2014 B3 08 LOOP2: MOVB BL,08H ;8 segments/character

2016 8A 04 MOVB AL,[SI] ;Get the display code


2019 D0 C0 LOOP1: ROLB AL,1 ;Get 1 data bit

201B BA E2 FF MOVW DX,0FFE2H

201E EE OUTB DX,AL ;Output bit to port B

201F 8A E0 MOVB AH,AL

2021 B0 01 MOVB AL,01H ;Output Clock to

2023 BA E4 FF MOVW DX,FFE4H ;Shift Register

2026 EE OUTB DX,AL

2027 FE C8 DECB AL

2029 EE OUTB DX,AL

202A 8A C4 MOVB AL,AH

202C FE CB DECB BL ;All bits over ?

202E 75 E9 JNZ LOOP1 ;No, Continue

2030 FE CD DECB CH ;All Characters

;over ?

2032 75 E0 JNZ LOOP2 ;No, Continue

2034 E8 06 00 CALL DELAY ;Introduce delay

2037 FE C9 DECB CL ;All groups over

2039 75 D7 JNZ LOOP3 ;No, Continue

203B E9 CF FF JMP LOOP4 ;Repeat continuously

203E 51 DELAY: PUSH CX ;Delay Subroutine

203F B9 FF FF MOVW CX,0FFFFH

2042 E2 FE LOOP $


21

2044 B9 FF FF MOVW CX,0FFFFH

2047 E2 FE LOOP $

2049 59 POP CX

204A C3 RET

2100 ORG 2100H ;Display Codes table

2100 FF FF FF FF DB 0FFH,0FFH,0FFH,0FFH

2104 C6 86 C7 86 DB 0C6H,086H,0C7H,086H


210C BF 92 91 92 DB 0BFH,092H,091H,092H

2110 92 C8 86 87 DB 092H,0C8H,086H,087H

5.0 EXERCISES

The sample program presented in this manual demonstrated some specific applications of this

interface. A few exercises are presented below to enable the user to gain a better understanding of

the interface. Users are encouraged to visualise other applications and develop software

accordingly.

a. Display the following sequence of digits in a right to left scrolling fashion with appropriate

delay.

1 2 3 4 5 6 7 8 9 0 -

b. Display time with the left two digits showing minutes and the right two digits showing

seconds. Use decimal point as delimiter.

c. The four digit display is required to show the outflow of fuel from a petrol pump. Initially,

the display should be as shown below:

Then increment the left two digits from 00 to 99 with a fixed delay. The right two digits should

constantly display Lt.

intel's mcs-51 family of microcontrollers and its ... viz 8085, z-80, 6502, ... 8c0d 7e mov a,m...

Documents