DS1985

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If a Page Address Redirection Byte has a FFH value, the data in the main memory that corresponds to that

page is valid. If a Page Address Redirection Byte has some other hex value, the data in the page

corresponding to that redirection byte is invalid, and the valid data can now be found at the one’s

complement of the page address indicated by the hex value stored in the associated Page Address

Redirection Byte. A value of FDH in the redirection byte for page 1, for example, would indicate that the

updated data is now in page 2. The details for reading and programming the EPROM status memory

portion of the DS1985 are given in the Memory Function Commands section.

DS 1985 MEMORY MAP Figure 4

REDIRECTION

BYTES

BIT MAP OF

USED PAGES

WRITE-PROTECT BITS

REDIRECTION BYTES

WRITE-PROTECT BITS

DATA MEMORY

STATUS MEMORY MAP

BIT 0 OF ADDRESS 000H=

WRITE PROTECT

OF PAGE 0, ETC.

ADDRESS 100H=PAGE ADDRESS

REDIRECTION BYTE FOR PAGE 0, ETC

.

8-BIT

SCRATCHPAD

88 BYTES

STATUS MEMORY