Adaptec SlimSCSI APA-1460, Техническое описание

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APA-1460 SlimSCSI Technical Reference
Stock Number: 510671-00, Rev. A
Page: 5-6
Print Spec Number: 492966-00, Rev. A
Current Date: 8/22/94
ECN Date: 8/30/94
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APA-1460 SlimSCSI Technical Reference
About the Updateable Attribute Memory
The total size of the Attribute Memory is 8 KBytes, ranging from 0000h to 1FFFh. Inter-
nally, an EEPROM is used to meet design requirements. During the Attribute Memory
Read cycle, there is no difference from reading regular memory. During the write cycle, a
special escape sequence must be followed to enable the write operation (see ATMEL data
sheets).
Sample code to enable the chip write protection:
write_enable proc
push es
push bx
push cx
mov ax, mapped_seg :select the segment
mov es, ax
mov bx, 1555h ; write AAh to 1555h
mov byte ptr es:[bx], 0aah
mov bx, 0aaah ; write 55h to 0AAAh
mov byte ptr es:[bx], 55h
mov bx, 1555h ; write A0h to 1555h
mov byte ptr es:[bx], 0a0h
pop cx
pop bx
pop es
ret
write_enable endp