LE25FS406

No.A1577-13/22

10. Silicon ID Read

ID read is an operation that reads the manufacturer code and device ID information. The silicon ID read command is not

accepted during writing. There are two methods of reading the silicon ID, each of which is assigned a device ID. In the

first method, the read command sequence consists only of the first bus cycle in which (9Fh) is input. In the subsequent

bus cycles, the manufacturer code 62h which is assigned by JEDEC, 2-byte device ID code (memory type, memory

capacity), and reserved code are output sequentially. The 4-byte code is output repeatedly as long as clock inputs are

present, "Table 7-1 JEDEC ID codes table" lists the silicon ID codes and "Figure 16-a JEDEC ID read" shows the

JEDEC ID read timing waveforms.

The second method involves inputting the ID read command. This command consists of the first through fourth bus

cycles, and the one bite silicon ID can be read when 24 dummy bits are input after (ABh). "Table 7-2 ID codes table"

lists the silicon ID codes and "Figure 16-b ID read" shows the ID read timing waveforms.

If the SCK input persists after a device code is read, that device code continues to be output. The data output is

transmitted starting at the falling edge of the clock for bit 0 in the fourth bus cycle and the silicon ID read sequence is

finished by setting CS high.

Table 7-1 JEDEC ID read

Table 7-2 ID read

Output code

Output Code

Manufacturer code

62h

Memory type

16h

1 byte device ID

3E

(LE25FS406)

2 byte device ID

Memory capacity code

13h(4M Bit)

Device code

1

00h

Figure 16-a Silicon ID Read 1

Figure 16-b Silicon ID Read 2

CS

High Impedance

13h

16h

62h

SCK

SO

SI

9Fh

15

MSB

MSB

MSB

0

1

2

3

4

5

6

7

8

23

16

24

31

39

8CL

Mode0

Mode3

32

00h

MSB

62h

MSB

CS

High Impedance

3Eh

3Eh

SCK

SO

SI

ABh

X

X

15

MSB

MSB

0

1

2

3

4

5

6

7

8

23

16

24

31

39

8CL

Mode0

Mode3

32

X