25C040-/P Microchip Technology, Inc., 25C040-/P Datasheet - Page 11

• Manufacturer Part Number: 25C040-/P
• Description: The 25AA040 is a 4K Bit Serial Electrically Erasable Prom With Memory Accessed Via a Simple Serial Peripheral Interface (SPI™) Compatible Serial Bus
• Manufacturer: Microchip Technology, Inc.

3.7
The following protection has been implemented to pre-
vent inadvertent writes to the array:
• The write enable latch is reset on power-up
• A write enable instruction must be issued to set
• After a byte write, page write or status register
• CS must be set high after the proper number of
• Access to the array during an internal write cycle
• The write enable latch is reset when the WP pin is
TABLE 3-3:
the write enable latch
write, the write enable latch is reset
clock cycles to start an internal write cycle
is ignored and programming is continued
low
2001 Microchip Technology Inc.
High
High
Low
WP
Data Protection
WRITE PROTECT FUNCTIONALITY MATRIX
WEL
X
0
1
Protected Blocks
Protected
Protected
Protected
25AA040/25LC040/25C040
Unprotected Blocks
3.8
The 25XX040 powers on in the following state:
• The device is in low power standby mode (CS = 1)
• The write enable latch is reset
• SO is in high impedance state
• A low level on CS is required to enter active state
Protected
Protected
Writable
Power On State
Status Register
Protected
Protected
Writable
DS21204C-page 11