MR25H40MDFR Everspin Technologies, MR25H40MDFR Datasheet - Page 7

• Manufacturer Part Number: MR25H40MDFR
• Description: NVRAM 4Mb 3.3V 512Kx8 SPI Pre-Qual Sample MRAM
• Manufacturer: Everspin Technologies

Specifications of MR25H40MDFR

• Rohs: yes
• Data Bus Width: 8 bit
• Memory Size: 4 MB
• Organization: 512 K x 8
• Interface Type: SPI
• Supply Voltage - Max: 3.6 V
• Supply Voltage - Min: 3 V
• Operating Current: 20 mA
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Package / Case: DFN-8
• Maximum Power Dissipation: 0.6 W
• Operating Temperature Range: - 40 C to + 85 C
• Operating Voltage: 3 V to 3.6 V

Everspin Technologies © 2011
SPI COMMUNICATIONS PROTOCOL
SCK
Read Data Bytes (READ)
CS
SO
The Read Data Bytes (READ) command allows data bytes to be read starting at an address specified by the
24-bit address. Only address bits 0-18 are decoded by the memory. The data bytes are read out sequen-
tially from memory until the read operation is terminated by bringing CS high The entire memory can be
read in a single command. The address counter will roll over to 0000h when the address reaches the top of
memory.
The READ command is entered by driving CS low and sending the command code. The memory drives the
read data bytes on the SO pin. Reads continue as long as the memory is clocked. The command is termi-
nated by bringing CS high.
SI
0
0
0
1
0
SCK
CS
SO
2
SI
Instruction (03h)
0
3
0
4
0
0
0
5
High Impedance
0
1
1
6
0
2
1
7
Instruction (01h)
0
MSB
23
3
8
0
4
22
Figure 2.4 WRSR
9
Figure 2.5 READ
0
5
21
10
High Impedance
24-Bit Address
0
6
7
1
7
3
28
MSB
7
8
2
29
6
9
1
30
5
10
Status Register In
0
31
4
11
MSB
7
32
3
12
6
33
2
13
5
34
1
14
Data Out 1
4
35
MR25H40 Rev. 5, 11/2011
0
15
3
36
Mode 3
Mode 0
MR25H40
2
37
1
38
0
39
7
Data Out 2