Octagon PC-500, User Manual

Page: 130 / 233

18-3
PC-500 user’s manual Serial EEPROM and CMOS RAM
Programming example:
/* Write 0x1234 to word 3*/
unsigned int seeData = 0x1234;
/* Inline assembly code for Borland C++ 3.1 */
asm {
mov ax,0fc01h
mov bx,03h /* Write word 3 */
mov cx,seeData /* Get write data from
c environment */
mov dx,0ffffh
int 17h
}
Read multiple words from the serial EEPROM
Function: fch
Subfunction: 02h
Purpose: To read multiple words from the on-board serial
EEPROM.
Calling registers: AH fch
AL 02h
BX Word address (zero based)
CX Word count
DX ffffh (relative to user area)
ES:DI Destination pointer
Return registers: Carry flag cleared if successful
AX
Word read
Carry flag set if error
AL
Error code
Error Code Meaning
ffh Unknown error
01h Function not implemented
02h Defective serial EEPROM
03h Illegal access
Comments: This function reads multiple words from the user
area of the serial EEPROM.
Programming example:
/* Read 10 words starting at word 5 */
unsigned int far *seeDataPtr = new unsigned int[10];
/* Allocate storage*/
/* Inline assembly code for Borland C++ 3.1 */
asm {
mov ax,0fc02h
mov bx,05h /* Read starts at word 5 */
mov cx,10 /* Read 10 words */
mov dx,0ffffh
les di,seeDataPtr
int 17h
}