CAT25080 CATALYST [Catalyst Semiconductor], CAT25080 Datasheet - Page 5

• Manufacturer Part Number: CAT25080
• Description: 8-Kb and 16-Kb SPI Serial CMOS EEPROM
• Manufacturer: CATALYST [Catalyst Semiconductor]

STATUS REGISTER
The Status Register, as shown in Table 2, contains a
number of status and control bits.
The RDY
busy with a write operation. This bit is automatically set
to 1 during an internal write cycle, and reset to 0 when
the device is ready to accept commands. For the host,
this bit is read only.
The WEL (Write Enable Latch) bit is set/reset by the
WREN/WRDI commands. When set to 1, the device is
in a Write Enable state and when set to 0, the device is
in a Write Disable state.
The BP0 and BP1 (Block Protect) bits determine which
blocks are currently write protected. They are set by the
Table 2. Status Register
Table 3. Block Protection Bits
Table 4. Write Protect Conditions
© 2006 Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
WPEN
¯¯¯¯ (Ready) bit indicates whether the device is
WPEN
7
BP1
Status Register Bits
0
0
1
1
X
X
0
0
1
1
6
0
BP0
0
1
0
1
High
High
Low
Low
¯¯¯
WP
X
X
5
0
Array Address Protected
WEL
25080: 0300-03FF
25160: 0600-07FF
25080: 0200-03FF
25160: 0400-07FF
25080: 0000-03FF
25160: 0000-07FF
0
1
0
1
0
1
4
0
None
5
user with the WRSR command and are non-volatile.
The user is allowed to protect a quarter, one half or the
entire memory, by setting these bits according to Table
3. The protected blocks then become read-only.
The WPEN (Write Protect Enable) bit acts as an enable
for the WP
when the WP
condition prevents writing to the status register and to
the block protected sections of memory. While
hardware write protection is active, only the non-block
protected memory can be written. Hardware write
protection is disabled when the WP
WPEN bit is 0. The WPEN bit, WP
combine to either permit or inhibit Write operations, as
detailed in Table 4.
Protected
Protected
Protected
Protected
Protected
Protected
Protected
BP1
Blocks
3
¯¯¯ pin. Hardware write protection is enabled
¯¯¯ pin is low and the WPEN bit is 1. This
BP0
2
Unprotected
Protected
Protected
Protected
Writable
Writable
Writable
Blocks
Quarter Array Protection
Half Array Protection
Full Array Protection
CAT25080, CAT25160
No Protection
Protection
¯¯¯ pin is high or the
WEL
¯¯¯ pin and WEL bit
1
Doc. No. 1122 Rev. A
Protected
Protected
Protected
Protected
Register
Writable
Writable
Status
¯¯¯¯
RDY
0