AT25DF081A-MH-T Atmel, AT25DF081A-MH-T Datasheet - Page 23

• Manufacturer Part Number: AT25DF081A-MH-T
• Description: IC FLASH 8MBIT SPI 8UDFN
• Manufacturer: Atmel

Specifications of AT25DF081A-MH-T

• Format - Memory: FLASH
• Memory Type: DataFLASH
• Memory Size: 8M (4096 pages x 256 bytes)
• Speed: 100MHz
• Interface: SPI, RapidS
• Voltage - Supply: 2.7 V ~ 3.6 V
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 8-UDFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

8715B–SFLSH–8/10
9.6
Read Sector Protection Registers
The Sector Protection Registers can be read to determine the current software protection status of each sector.
Reading the Sector Protection Registers, however, will not determine the status of the WP pin.
To read the Sector Protection Register for a particular sector, the CS pin must first be asserted and the opcode of
3Ch must be clocked in. Once the opcode has been clocked in, three address bytes designating any address
within the sector must be clocked in. After the last address byte has been clocked in, the device will begin output-
ting data on the SO pin during every subsequent clock cycle. The data being output will be a repeating byte of
either FFh or 00h to denote the value of the appropriate Sector Protection Register.
At clock frequencies above f
quencies above f
correct status of the appropriate Sector Protection Register.
Table 9-3.
Deasserting the CS pin will terminate the read operation and put the SO pin into a high-impedance state. The CS
pin can be deasserted at any time and does not require that a full byte of data be read.
In addition to reading the individual Sector Protection Registers, the Software Protection Status (SWP) bits in the
Status Register can be read to determine if all, some, or none of the sectors are software protected (refer to
Status Register” on page 31
Figure 9-5.
SCK
SO
Output Data
CS
SI
00h
FFh
Read Sector Protection Register – Output Data
Read Sector Protection Register
HIGH-IMPEDANCE
MSB
0
CLK
0
Sector Protection Register Value
Sector Protection Register value is 0 (sector is unprotected)
Sector Protection Register value is 1 (sector is protected)
0
1
, at least two bytes of data must be clocked out from the device in order to determine the
1
2
OPCODE
1
3
1
4
for more details).
CLK
1
5
, the first byte of data output will not be valid. Therefore, if operating at clock fre-
0
6
0
7
MSB
A
8
A
9
ADDRESS BITS A23-A0
A
10 11
A
A
12
A
A
29 30
A
A
31 32
MSB
D
D
33
DATA BYTE
D
34
D
35
D
36
Atmel AT25DF081A
D
37 38
D
D
39 40
MSB
D
D
“Read
23