M95640 ST Microelectronics, M95640 Datasheet - Page 17

• Manufacturer Part Number: M95640
• Description: 64/32/16/8 Kbit Serial SPI Bus EEPROM With High Speed Clock
• Manufacturer: ST Microelectronics

Figure 13. Read from Memory Array (READ) Sequence
Note: Depending on the memory size, as shown in Table 6, the most significant address bits are Don’t Care.
Read from Memory Array (READ)
As shown in Figure 13, to send this instruction to
the device, Chip Select (S) is first driven Low. The
bits of the instruction byte and address bytes are
then shifted in, on Serial Data Input (D). The ad-
dress is loaded into an internal address register,
and the byte of data at that address is shifted out,
on Serial Data Output (Q).
If Chip Select (S) continues to be driven Low, the
internal address register is automatically incre-
mented, and the byte of data at the new address is
shifted out.
S
C
D
Q
0
1
High Impedance
2
Instruction
3
4
5
6
7
MSB
15
8
14 13
9 10
16-Bit Address
3
20 21 22 23 24 25 26 27
When the highest address is reached, the address
counter rolls over to zero, allowing the Read cycle
to be continued indefinitely. The whole memory
can, therefore, be read with a single READ instruc-
tion.
The Read cycle is terminated by driving Chip Se-
lect (S) High. The rising edge of the Chip Select
(S) signal can occur at any time during the cycle.
The first byte addressed can be any byte within
any page.
The instruction is not accepted, and is not execut-
ed, if a Write cycle is currently in progress.
2
1
0
MSB
7
6
5
Data Out 1
4
3
28 29 30
2
1
0
31
M95640, M95320
7
Data Out 2
AI01793D
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