25LC640AXT-E/ST Microchip Technology, 25LC640AXT-E/ST Datasheet - Page 10

• Manufacturer Part Number: 25LC640AXT-E/ST
• Description: 64K, 8K X 8, 2.5V SER EE EXT, ROTATED PINOUT 8 TSSOP 4.4mm T/R
• Manufacturer: Microchip Technology

Specifications of 25LC640AXT-E/ST

• Format - Memory: EEPROMs - Serial
• Memory Type: EEPROM
• Memory Size: 64K (8K x 8)
• Speed: 10MHz
• Interface: SPI, 3-Wire Serial
• Voltage - Supply: 2.5 V ~ 5.5 V
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 8-TSSOP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 25LC640AXT-E/STTR

25AA640A/25LC640A
2.5
The Read Status Register instruction (RDSR) provides
access to the STATUS register. The STATUS register
may be read at any time, even during a write cycle. The
STATUS register is formatted as follows:
TABLE 2-2:
The Write-In-Process (WIP) bit indicates whether the
25XX640A is busy with a write operation. When set to
a ‘
is in progress. This bit is read-only.
FIGURE 2-6:
DS21830D-page 10
W/R = writable/readable. R = read-only.
WPEN
SCK
1
W/R
CS
SO
’, a write is in progress, when set to a ‘
7
SI
Read Status Register Instruction
(RDSR)
6
–
X
0
5
–
X
0
READ STATUS REGISTER TIMING SEQUENCE (RDSR)
STATUS REGISTER
X
4
–
0
1
W/R
BP1
High-Impedance
3
0
Instruction
2
W/R
BP0
0
2
3
0
WEL
4
R
1
0
’, no write
1
5
WIP
R
0
0
6
1
7
The Write Enable Latch (WEL) bit indicates the status
of the write enable latch and is read-only. When set to
a ‘
‘
this bit can always be updated via the WREN or WRDI
commands regardless of the state of write protection
on the STATUS register. These commands are shown
in Figure 2-4 and Figure 2-5.
The Block Protection (BP0 and BP1) bits indicate
which blocks are currently write-protected. These bits
are set by the user issuing the WRSR instruction. These
bits are nonvolatile, and are shown in Table 2-3.
See Figure 2-6 for the RDSR timing sequence.
7
0
8
’, the latch prohibits writes to the array. The state of
1
’, the latch allows writes to the array, when set to a
6
9
Data from STATUS Register
10
5
11
4
© 2008 Microchip Technology Inc.
12
3
13
2
14
1
15
0