Datasheet

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M950x0-W M950x0-R M950x0-DF Instructions
44
6.9 Read Lock Status (available only in M95040-D device)
The Read Lock Status (RDLS) instruction is used to read the lock status.
To send this instruction to the device, Chip Select (S) first has to be driven low. The bits of
the instruction byte and address bytes are then shifted in (MSB first) on Serial Data input
(D). Address bit A7 must be 1; all other address bits are Don't Care (it might be easier to
define these bits as 0, as shown in
Table 5). The Lock bit is the LSB (Least Significant Bit) of
the byte read on Serial Data output (Q). It is at ‘1’ when the lock is active and at ‘0’ when the
lock is not active. If Chip Select (
S) continues to be driven low, the same data byte is shifted
out.
The read cycle is terminated by driving Chip Select (S) high. The instruction sequence is
shown in
Figure 16.
The Read Lock Status instruction is not accepted and not executed if a Write cycle is
currently in progress.
Figure 16. Read Lock Status sequence
C
D
MS31630V1
S
Q
A7
21 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
A6 A5 A4 A3 A2 A1 A0
20 21 22
76543
2
0
1
High Impedance
Data Out
Instruction Byte Address
0