Octagon 6000 Series, User Manual

Page: 82 / 233

6-17
6000 Series user’s manual EZ I/O
xxxxxxxxB direction; 1->output, 0->input
BX Port B configuration
xxxxxxxx xxxxxxxxB
xxxxxxxx
Initial data for port B
xxxxxxxxB direction; 1->output, 0->input
CX Port C configuration
xxxxxxxx xxxxxxxxB
xxxxxxxx
Initial data for port C
xxxxxxxxB direction; 1->output, 0->input
DX ffffh
Return registers: Carry flag cleared if successful
Carry flag set if error
AL
Error code
Comments: This function is used to initialize the first EZ I/O (i.e., the EZ
I/O that has the lower I/O address when two EZ I/O chips are
present on a board) before normal use.
Programming example:
/* Inline assembly code for Borland C++ 3.1 */
asm {
mov ax,0ef00h
mov di,00ffh /*port A all outputs, init data=all 0’s */
mov bx,55ffh /*port B all outputs, init data=55h*/
mov cx,0000h /*port C all inputs*
mov dx,0ffffh
int 17h
}
Write EZ I/O (1)
Function: efh
Subfunction: 01h
Purpose: To write a value of an EZ I/O port.
Calling registers: AH efh
AL
01h
DI Port A mask and data
xxxxxxxx xxxxxxxxB
xxxxxxxx
Mask for port A; 1->bit to be
changed
xxxxxxxxB Data for port A
BX Port B mask and data
xxxxxxxx xxxxxxxxB
xxxxxxxx
Mask for port B; 1->bit to be
changed
xxxxxxxxB Data for port B
CX Port C mask and data
xxxxxxxx xxxxxxxxB
xxxxxxxx
Mask for port C; 1->bit to be
changed