Przykład oprogramowania protokołu

komunikacyjnego dla łącza równoległego

pomiędzy procesorem “master” i wieloma

procesorami “slave”

Założenia projektu (widziane od strony “slave”)

–

szyny adresów i danych: 8 linii portu P0

–

sygnały odbierane: INT0 = address strobe,
INT1=data strobe, R/W=kierunek przesyłu
danych,

–

sygnał wysyłany: ACK – potwierdzenie
odbioru/ wysłania bajtu

–

adres (numer) procesora “slave” 5-cio bitowy,
uzupełniony dodatkowymi informacjami na
MSB (most significant bits), które zapowiadają
jeden z czterech typów dialogu: czytanie
krótkie, czytanie długie, pisanie krótkie i
długie. Czytanie i pisanie długie wymaga
zawsze odebrania dodatkowego byte
adresowego (jako pierwszego bajtu danych
adresowanego do wybranego już “slave”)

Poniżej pokazane są czasowe przebiegi i relacje sygnałów na liniach

adresów/danych oraz na liniach sterujących, pobrane z analizatora stanów
logicznych

MIKROPROCESORY i MIKROKONTROLERY

;====================================================================
;

DEFINITIONS

; =================================================================
STACK

DATA

0E0H

;

FLAGS

DATA

22H

;S B R bits (S=1 set) (B=1 data for board, =0 chan)

SETF

BIT

22H.7

BFLAG

BIT

22H.6

;
SYGNA

DATA

23H

FIRST

BIT

23H.0

;
MASK

DATA

2DH

M_CH0

BIT

2DH.0

M_CH1

BIT

2DH.1

M_CH2

BIT

2DH.2

M_CH3

BIT

2DH.3

M_CH4

BIT

2DH.4

M_CH5

BIT

2DH.5

M_CH6

BIT

2DH.6

M_CH7

BIT

2DH.7

;

STAT_B

DATA

2FH

BUSY

BIT

2FH.6

;
BUFCIO

DATA

030H

;2-BYTE bufin for read command

CCODE

DATA

031H

B_ID

DATA

040H

;board reads it from hardware position

QUECH

DATA

041H

;circulating bit

ACTIVE

DATA

042H

;bits set for actually powered channels

CHAON

DATA

043H

;channels waiting for ON

CNB

DATA

044H

;byte count - serial transport

HANDY

DATA

045H

;

CH2RD

DATA

046H

;Channel to report

LASTON

DATA

047H

;counts ticks before next channel is on

NSETCH DATA

048H

;new settings for this channel - as integer 0-7

BSETCH

DATA

049H

; " " ... as bit position

CZESTO

DATA

04AH

;controls asking freq

CLRBFS

DATA

04BH

;channels recently OFF, buffers to be cleared

;
BUFF

DATA

050H

;for input

; +0

first word readin at DS - usually contains chan address in 765

; +1

NBYTE

; +2

CCODE (for channel controler)

; +3 - +15 (+F)
; VREQH, VREQL,
CT0H,CTOL,CT1H,CT1L,CT2H,CT2L,CT3H,CT3L,RCODE,ENDCODE
ECOD

DATA

05EH

;ENDCODE

BUF0

DATA

060H

;channel brings measurements,for ch0

BUF1

DATA

070H

;for ch 1

BUF2

DATA

080H

;for ch 2

BUF3

DATA

090H

;for ch 3

BUF4

DATA

0A0H

;for ch 4

BUF5

DATA

0B0H

;for ch 5

BUF6

DATA

0C0H

;for ch 6

BUF7

DATA

0D0H

;for ch 7

;
R_W

BIT

P1.5

;set = we reading what crate says

;
BS

BIT

P2.5

IRQ

BIT

P2.6

ACK

BIT

P2.7

;
AST

BIT

P3.2

DST

BIT

P3.3

;
CSEG
ORG

00H

;
;------------------------------------------------------------------------------

AJMP

start

;----------------------------------------INTERRUPT SERVICES---------------
ORG

03H

;INT0 (IE0) ADRESS STROBE (AS) service

AJMP

asint

;------------------------------------------------------------------------------
ORG

00BH

;TIMER0 interrupt service

AJMP

tnul

;------------------------------------------------------------------------------
ORG

013H

;INT1 (IE1) DATA STROBE service

AJMP

dsint

;------------------------------------------------------------------------------
ORG

01BH

;TIMER1 interrupt service

AJMP

tone

;------------------------------------------------------------------------------

;------------------------------------------------------------------------------
;
ORG

70H

;------------------------------------------------------------------------------
; PARTS OF INTERRUPT SERVICES AND SUBROUTINES
;------------------------------------------------------------------------------
asint:

;AS - for me?

PUSH

ACC;

PUSH

PSW

SETB

RS0

;registers from bank1

CLR

RS1

;too much care?

CLR

EX1

;to be quiet if AS not for this board

CLR

FIRST

;marks the beginning of the DATA chain

CLR

BS

;clock it in

MOV

A,P0

;brings S B R flags and BADDR

SETB

BS

MOV

FLAGS,A

ANL

A,#1FH

;get board address part

XRL

A,B_ID

;compare with my ID

JNZ

asrtn

;NO

CLR

ACK

;YES

MOV

A,FLAGS ;interpret flags

ANL

A,#0C0H

;S B only

SETB

EX1

;enable following DATA STROBES

JNB

AST,$

SETB

ACK

;protocol

;

CJNE

A,#00H,nomch

MOV

R0,#BUFF ;monitor channel

SJMP

asrtn

;
nomch:

CJNE

A,#40H,nomb

MOV

R1,#STAT_B

;monitor board

SJMP

asrtn

;
nomb:

CJNE

A,#80H,nostch

MOV

R0,#BUFF ;set channel

SETB

BUSY

SJMP

asrtn

;
nostch:

CJNE

A,#0C0H,asrtn

MOV

R0,#MASK ;set board

asrtn:

POP

PSW

POP

ACC

RETI

;
;----------------------------------------------------------------------------
dsint:

PUSH

ACC

PUSH

B

PUSH

PSW

SETB

RS0

;Bank 1

CLR

RS1

CLR

BS

JB

R_W,sets

;---crate controler READS data, ergo here writing to P0

MOV

P0,@R1

CLR

ACK

INC

R1

JNB

DST,$

SETB

BS

MOV

P0,#0FFH

;ready to read

SJMP

dsrtn

;
sets:

;we are reading what CrateControl says

MOV

@R0,P0

CLR

ACK

JB

FIRST,dscdn

;prepare further reading

JB

BFLAG,dscdn

;or if board command already satisfied

SETB

FIRST

;to skip it later

MOV

A,@R0

;first data byte has chan address in 765

bits

ANL

A,#0F0H

SWAP

A

RR

A

MOV

B,#10H

MUL

AB

ADD

A,#BUF0

MOV

R1,A

;for subsequent reading of given chan

dscdn:

INC

R0

SETB

BS

JNB

DST,$

dsrtn:

SETB

ACK

POP

PSW

POP

B

POP

ACC

RETI

;
;------------------------------------------------------------------
tnul:

PUSH

ACC

PUSH

PSW

SETB

0AH

MOV

A,LASTON

JZ

tn1

DEC

LASTON

tn1:

MOV

TH0,#00H

MOV

TL0,#00H

POP

PSW

POP

ACC

RETI

;------------------------------------------------------------------
tone:

PUSH

ACC

PUSH

PSW

MOV

A,CZESTO

JZ

ton1

DEC

CZESTO

ton1:

POP

PSW

POP

ACC

RETI

;===================================================================

;======================================================INITIAL PART==
start:

MOV

SP,#STACK

MOV

R0,#050H

CLR

A

zero:

MOV

@R0,A

INC

R0

;clear buffers

CJNE

R0,#STACK+1,zero

;

MOV

STAT_B,A ;clear board status

;

MOV

P1,#00H

;funny port input

MOV

A,P1

ANL

A,#01FH

MOV

B_ID,A

;5-bit board identifier

;

MOV

P0,#0FFH

;ready for input

;

SETB

EA

;interrupts allowed

SETB

EX0

;from external 0 (always ON for AddressStrobe)

SETB

ET0

;from TIMER0

SETB

ET1

; TIMER1

SETB

ES

; serial port

;
;
;
;
; Tu miejsce na główny program ...
;
END