MB85AS12MT

8

DS501-00071-1v1-E



READ

The READ command reads ReRAM memory cell array data. Arbitrary 24 bits address and op-code of READ

are input to SI. The 3-bit upper address bit is invalid. And in case of designating address other than effective

region (180000H to 1FFFFFH), the command itself is ignored. Then, 8-cycle clock is input to SCK. SO is

output synchronously to the falling edge of SCK. While reading, the SI value is invalid. When CS is risen,

the READ command is completed, but keeps on reading with automatic address increment which is enabled

by continuously sending clocks to SCK in unit of 8 cycles before CS rising. When it reaches the most

significant address (17FFFFH), it rolls over to the starting address, and reading cycle keeps on infinitely.



WRITE

The WRITE command writes data to ReRAM memory cell array. WRITE op-code, arbitrary 24 bits of address

and 8 bits of writing data are input to SI. The 3-bit upper address bit is invalid. And in case of designating

address other than effective region (180000H to 1FFFFFH), the command itself is ignored. During the CS is

low, input writing data are temporary saved in the data register. The maximum writing data size is 256 bytes

during this CS = low period. If the input writing data are more than 8 bits, it is possible to continue writing

with automatic address increment. When it reaches the most significant address, it rolls over to the starting

address, and writing cycle can be continued up to 256 bytes (which is the size of data register). Data exceed

256 bytes can not be written.

After rising edge of CS, MB85AS12MT starts writing operation to nonvolatile memory and set WIP bit in

status register to “1”. After this writing operation has finished, reset this WIP bit from “1” to “0”. Although the

RDSR command is executable for WIP polling during this writing process, any other commands will not be

performed.

CS

SCK

SI

Invalid

MSB

LSB

MSB

Data Out

LSB

High-Z

Invalid

45

0123

26 27

6 7 8 9 10 11 12 13 14 15

38 39

28 29 30 31 32 33 34 35 36 37

00000011 X

32

X X 20 19 18 17 16

54

SO

76

3

10

54

210

CS

SCK

Data In

SI

MSB

LSB

MSB

LSB

High-Z

10 11

0123456789

14 15

26

31 32

12 13

27 28 29 30

33 34 35 36 37 38 39

0000001

3

0 X X X 20 19

2

1

0

SO

18 17 16

5

4

3

2

1

0

7654