X76F041 Datasheet, PDF (9/21 Pages) Xicor Inc. – PASS TM SecureFlash

X76F041
READ OPERATION
Random Read with Password
Random read with password operations are initiated
with a START command followed by the read command
and the address of the first byte of the block in which data
is to be read:
Block 0 = 000h
Block 1 = 080h
Block 2 = 100h
Block 3 = 180h
Figure 8. Random Read with Password
This is followed by the eight byte read password
sequence which includes the 10ms wait time and the
password acknowledge polling sequence. If the pass-
word is accepted an “ACK” will be returned followed by
eight bits of “secure read setup” which is to be ignored. At
this point a START is issued followed by the address and
data to be read within the original 1K block. See figure 8.
Once the first byte has been read, another start can be
issued followed by a new 8-bit address. Random reads
are allowed only within the original 1K-bit block. To
access another 1K-bit block, a stop must be issued fol-
lowed by a new command/block address/password
sequence.
SDA LINE
FIRST BYTE
S
BLOCK ADDRESS
T
A
R
T
C
M
D
A
X
A
X
A
X
A
X
A
8
AAAAAAAA
76543210
READ
PASSWORD 7
S
A
A
A
C
C
C
K
K
K
READ
PASSWORD 0
WAIT
tWC/ACK POLLIN
A
A
C
C
K
K
IF PASSWORD
MATCH THEN
SECURE
READ SETUP
S
T
A
RA ^{A A A A A A A}
T7 ^{6 5 4 3 2 1 0}
XXXXXXXXS
DATA 0
S
T
A
RA ^{A A A AA A A}
T7 ^{6 5 4 32 1 0}
S
S
DATA 1
T
O
P
S
A
A
A
C
C
C
K
K
K
7002 ILL F13
9