Octagon PC-510, User Manual

Page: 135 / 239

17-4
Serial EEPROM and CMOS RAM PC-510 user’s manual
Write multiple words to the serial EEPROM
Function: fch
Subfunction: 03h
Purpose: To write multiple words to the on-board serial
EEPROM.
Calling registers: AH fch
AL 03h
BX Word address (zero based)
CX Word count
DX ffffh (user area relative address)
DS:SI Source pointer
Return registers: Carry flag cleared if successful
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 writes multiple words to the user area
of the serial EEPROM.
Programming example:
/* Write 8 words starting at word 6*/
unsigned int far *seeDataPtr = new unsigned int[8];
/* Allocate storage*/
unsigned int far* tmpPtr = seeDataPtr;
for(int i=0;i<8;i++)
*seeDataPtr = i;/* initialize data */
/* Inline assembly code for Borland C++ 3.1 */
asm {
push
ds
mov ax,0fc03h
mov bx,06h /* Write starts at word 6 */
mov cx,8 /* Write 8 words */
mov dx,0ffffh
lds si,seeDataPtr
int 17h
pop ds
}
Return serial EEPROM size
Function: fch
Subfunction: 04h
Purpose: To obtain the size of the on-board serial EEPROM.