Архив форумов ЦИТФорума

[VictorV]

Необходимо считывать данные с LPT порта в Windows 2400 раз в секунду - очень нужно !!!!
Заранее спасибо

[ilya]

//---------------- PC's internal port addresses --------------------------------------

#define WDATA 0x0378 // PC's internal port address to wrirte out the data byte
#define RDATA 0x0379 // PC's internal port address to read in the 4 bit of data byte
#define CONTR 0x037A // PC's internal port address to wrirte strobs

//---------------- Controls ---------------------------------------------------------

// |C0-LSWR|C1-ALE|C2-RDEN|C3-DSTRB all the pins are inverse

#define INIT 0x00 // Init state of control pins
#define CLRLSWR 0x01 // LSWR low level
#define CLRALE 0x02 // ALE low level
#define SETRDEN 0x04 // RDEN high level

// use this define in write cycle only
#define WCLRDSTRB 0x08 // DSTRB low level (write)

//_________________________________________________
// |
// This defines are for read cycle only |
// |
#define RCLRDSTRB 0x0C // DSTRB low level(read) |
#define RSETDSTRB 0x04 // DSTRB hight level(read)|
//________________________________________________|

.. ReadByte()
{
BYTE Result;

__asm
{
push dx
push ax
push cx ; put cx to the stack


mov dx ,CONTR ; load CONTROL port address to DX
mov al,CLRALE ; load control byte (with ALE = 0) to AL
out dx,al ; set the address latch enable to low level(ALE = 0)
mov al,INIT ; load control byte (with ALE = 1) to AL
out dx,al ; set the address latch enable to low level(ALE = 1)

mov al,SETRDEN ; load control byte (with RDEN = 1) to AL
out dx,al ; set the read latch signal to high level(RDEN = 1)

mov al,RCLRDSTRB; load control byte(with DSTRB = 0) to AL
out dx,al ; set the data latch signal to low level(DSTRB = 0)
mov al,RSETDSTRB; load control byte(with DSTRB = 1) to AL
out dx,al ; set the data latch signal to high level(DSTRB = 1)


mov dx, RDATA ; load read DATA port address to DX
in al, dx ; take the read value from the port to AL
; AL3 = D0 , AL4 = D1 , AL5 = D2 , AL7 = D3


mov ch,al ; save low 4 bits of read value in CH

mov dx ,CONTR ; load CONTROL port address to DX
mov al,INIT ; load control byte (with RDEN = 0) to AL
out dx,al ; set the read latch signal to high level(RDEN = 0)

mov dx, RDATA ; load read DATA port address to DX
in al, dx ; take the read value from the port to AL
; AL3 = D4 , AL4 = D5 , AL5 = D6 , AL7 = D7

shl ch,1 ; shift left CH 1 time
jnc Lab1
and ch,7Fh ; set CH7 to 0
jmp Lab2
Lab1:
or ch,80h ; set CH7 to 1
Lab2:
mov cl,4 ; load shift counter in CL
shr ch,cl ; clear CH4-CH7
mov Result,ch ; load D0-D3 to Result

shl al,1 ; shift left AL 1 time
jnc Lab3
and al,7Fh ; set AL7 to 0
jmp Lab4
Lab3:
or al,80h ; set AL7 to 1
Lab4:
and al, ...

[ilya]

А это если не нужен Контроль Регистр


int Port=0x378;
int InPort()
{
unsigned char Res;
__asm
{
mov edx, Port
in al, dx
mov Res,al
}
return (int)Res;
}

[VictorV]

Мне надо 2400 РАЗ В СЕКУНДУ опрашивать LPT порт под Виндой - как настроить скорость??