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8051 8051 [email protected]://blog.naver.com/dolicom
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?CPU , . CPU
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. . . . . . .
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PC PC
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Interrupts vs. Polling : CPU (polling) : CPU CPU .
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: Maskable Interrupt 8051 (IE ) : CPU ) 8051
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ISR Interrupt Service Routine 8051, Z80, 8080 . . (Interrupt
Vector Table) 80x86, 68000
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PC . MOV SP,#60H 8051 RAM 0x61 C startup.obj . (ISR) .
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CPU . ISR . ISR .
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A, B, PSW R0~R7 PC SP .
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. PC ISR PC A, B, PSW, Rn .Rn,PSW,B,A RETI PC
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I . CPU PC . 16 PC .ISR . ISR . PSW . .
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IIISR . . POP (POP PSW) PUSH POP .PUSH RETI ISR PC . (RETI )
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C void SerialEcho(void) interrupt 0{ char ch; if (RI == 1) { RI
= 0; ch = SBUF; SBUF = ch; } else { TI = 0; } } ; FUNCTION
SerialEcho (BEGIN)PUSH PSWMOV PSW,#00HPUSH AR7
JNB RI,?C0002CLR RI; Variable 'ch' assigned to Register 'R7' MOV
R7,SBUFMOV SBUF,R7SJMP ?C0004?C0002:CLR TI?C0004:
POP AR7POP PSWRETI
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CPURAMROM4 I/O Timer 0Serial PortOSCInterrupt Control Timer
1Timer/CounterBus ControlTxD RxDP0 P1 P2 P3
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5 0 0x03/ 0 0x0B 1 0x13/ 1 0x1B 0x23
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IE(Interrupt Enable) mask IP(Interrupt Priority) TCON SCON
CPU
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(IE) . (IP) . , (IE0, IE1, TF0, TF1) . RI,TI .
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Interrput
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I TCON SCON .1 TF1TR1TF0TR0IE1IT1IE0IT0Timer 1 Timer0Interrupt7
6 5 4 3 2 1 0IE0 : External Interrupt 0 edge flagTF0 : 0 overflow
Timer 0 Overflow flagIE1 : External Interrupt 1 edge flagTF0 : 1
overflow Timer 1 Overflow flag
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IISCON SM0SM1SM2RENTB8RB8TIRI7 6 5 4 3 2 1 0TI : Transmit
Interrupt flagRI : Receive Interrupt flag
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IE(Interrupt Enable) Mask Mask Bit : . 1 EA CPU . 0 CPU EA=1
(ES,ET1,EX1,ET0,EX0) .EA--ESET1EX1ET0EX07 6 5 4 3 2 1 0EA (Enable
All Interrupt) : 1 = ES (Enable Serial Interrupt) : 1 = RI & TI
ET1 (Enable Timer1 Interrupt) : 1 = 1 EX1 (Enable eXternal1
Interrupt) : 1 = 1 ET0 (Enable Timer0 Interrupt) : 1 = 0 EX0
(Enable eXternal0 Interrupt) : 1 = 0
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IP(Interrupt Priority) ISR .---PSPT1PX1PT0PX07 6 5 4 3 2 1 0PS
(Serial port priority control) : 1 = PT1 (Timer1 priority control)
: 1 = 1 PX1 (external interrupt1 priority control) : 1 = 1 PT0
(Timer0 priority control) : 1 = 0 PX0 (external interrupt0 priority
control) : 1 = 0
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/INT0, /INT1 2 (0 ) TF1TR1TF0TR0IE1IT1IE0IT07 6 5 4 3 2 1 0IT0
(Interrupt 0 Type control) IT0=1 : /INT0(P3.2) () IT0=0 :
/INT0(P3.2) L IT1 (Interrupt 1 Type control) IT1=1 : /INT1(P3.3) ()
IT1=0 : /INT1(P3.3) L
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C (ISR) . . ISR C51 . ISR . .
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ISR 0 0 0x03/ 0 1 0x0B 1 2 0x13/ 1 3 0x1B 4 0x23
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void ISR_Name(void) interrupt 3 using 2 ISR_Name : interrupt 3 :
( ) 0 ~4 (4-2) using 2 : ( ) - 0~7
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ISR 0 #include
void Ex_KeyUp(void) interrupt 0 using 1{ . . . // } 0
#include
void Tm0_Clock(void) interrupt 1{ . . . // }
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ISR II
#include
void SerialEcho(void) interrupt 0 using 1{ char ch; if (RI == 1)
{ RI = 0; ch = SBUF; // SBUF = ch; // } else { TI = 0; } }
