IS25C04 查看數據表（PDF） - Integrated Silicon Solution
零件编号
产品描述 (功能)
生产厂家
IS25C04 Datasheet PDF : 17 Pages
| |||
IS25C02
IS25C04
ISSI ®
STATUS REGISTER
The status register contains 8-bits for write protection
control and write status. (See Table 1). It is the only
region of memory other than the main array that is
accessible by the user.
Table 1. Status Register Format
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit1 Bit 0
X
X X X BP1 BP0 WEN RDY
Notes:
1. X = Don't care bit.
2. During internal write cycles, bits 0 to 7 are temporarily 1's.
The Status Register is Read-Only if either: a) Hardware
Write Protection is enabled or b) WEN is set to 0. If
neither is true, it can be modified by a valid instruction.
Ready (RDY), Bit 0: When RDY = 1, it indicates that
the device is busy with a write cycle. RDY = 0 indi-
cates that the device is ready for an instruction. If RDY
= 1, the only command that will be handled by the
device is Read Status Register.
Write Enable (WEN), Bit 1: This bit represents the
status of device write protection. If WEN = 0, the Status
Register and the entire array is protected from modifica-
tion, regardless of the setting of WP pin or block protec-
tion. The only way to set WEN to 1 is via the Write
Enable command (WREN). WEN is reset to 0 upon
power-up, successful completion of Write, WRDI,
WRSR, or WP being Low.
Block Protect (BP1, BP0), Bits 2-3: Together, these
bits represent one of four block protection configurations
implemented for the memory array. (See Table 2 for
details.)
BP0 and BP1 are non-volatile cells similar to regular
array cells, and factory programmed to 0. The block of
memory defined by these bits is always protected,
regardless of the setting of WP or WEN.
Table 2. Block Protection
Status
Register
Bits
Array Addresses Protected
Level
0
1(1/4)
2(1/2)
3(All)
BP1 BP0
00
01
10
11
IS25C02
None
C0h
-FFh
80h
-FFh
00h
-FFh
IS25C04
None
180h
-1FFh
100h
-1FFh
000h
-1FFh
Don’t Care, Bits 4-7: Each of these bits can receive
either 0 or 1, but values will not be retained. When
these bits are read from the register, they are always 0.
4
Integrated Silicon Solution, Inc. — 1-800-379-4774
Preliminary Information Rev. 00F
12/22/05
Share Link: 