Octagon XE-900, Reference Manual

Page: 85 / 122

85
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 (bytes) of the on–board
serial EEPROM.
Calling registers: AH fch
AL 04h
DX ffffh
Return registers: Carry flag cleared if successful
AX Size of the serial EEPROM (1536 + 512)
BX Size available to user (512 bytes)
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 returns the size (in bytes) of the
serial EEPROM. Since the user cannot access all
of the serial EEPROM, this function determines
how much space is available to the user. This
avoids the user from accessing unavailable
addresses.
Programming example:
unsigned int seeUserSize;
/* Inline assembly code for Borland C++ 3.1*/
asm {
mov ax,0fc04h
mov dx,0ffffh
int 17h
mov seeUserSize,bx
}