PM25LV010 データシートの表示（PDF） - PMC-Sierra, Inc
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PM25LV010
PMC-Sierra, Inc
PM25LV010 Datasheet PDF : 32 Pages
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PMC
REGISTERS (CONTINUED)
Pm25LV010/020/040
CONFIGURATION REGISTER
The Configuration Register is built by latchs need to be
set each time after power-up before enabling the 1 Kbyte
smaller sector size and 1 Kbyte sector write protection.
The Bit 0 - Bit 7 of Configuration Register are set as “0”s
after power-up reset. Therefore, the devices will be al-
ways set as normal mode - the bottom sector set as 4
Kbyte by default after power-up to maintain the back-
ward-compatibility.
The function of Configuration Register is described as
following:
The BP0, BP1, BP2, and SRWD are non-volatile memory
cells that can be written by Write Status Register (WRSR)
instruction. The default value of BP0, BP1, BP2, and
SRWD bits were set as “0” at factory. Once those bits
are written as “0” or “1”, it will not be changed by devices
power-up or power-down until next WRSR instruction al-
ters its value. The Status Register can be read by Read
Status Register (RDSR) instruction for its value and sta-
tus. Refer to Table 8 for Instruction Set.
The function of Status Register is described as following:
SCFG bit: The 1 Kbyte smaller sector mode is enabled
by writing “1” to SCFG bit, then Sector 0 is configured
as Sector 0_0, Sector 0_1, Sector 0_2 and Sector 0_3.
A Sector Erase (SECTOR_ER) instruction can be used
to erase any one of those four 1 Kbyte sectors. The
SCFG bit will be reset “0” state automatically at power
on stage. Thus, the 1 Kbyte smaller sector mode is
disabled at power on till SCFG bit was set.
The SCFG bit only can be enabled to “1” when BP0,
BP1&BP2 of status register were “1” state which in pro-
tection mode. On the other word, SCFG bit will be cleared
to “0” state when BPx were “0” to disable the protection
mode.
SP0_x bits: The write protection to those four 1 Kbyte
sectors can be activated by writing “1”s to the SP0_0,
SP0_1, SP0_2 and SP0_3 bits. The 1 Kbyte sector write
protection function can only be enabled when the SCFG
is also enabled.
The Write Configuration Register (WRCR) instruction can
be used to write “0”s or “1”s into Configuration Register.
And the Read Configuration Register (RDCR) instruc-
tion can be used to read the setting of Configuration
Register. Refer to Table 8 for Instruction Set.
STATUS REGISTER
The Status Register contains WIP and WEL status bits
to indicate the status of the devices, the Block Protec-
tion Bits (BP0, BP1 and BP2 (Pm25LV040 only)) to
define the portion of memory blocks to be write protected,
and SRWD control bits to be set for status register write
protection. Refer to Table 3 and Table 4 for Status Reg-
ister Format and Status Register Bit Definition.
WIP bit: The Write In Progress (WIP) bit can be used to
detact the progress or completion of program or erase
operation. When WIP bit is “0”, the devices are ready for
write status register, program or erase operation. When
WIP bit is “1”, the devices are busy.
WEL bit: The Write Enable Latch (WEL) bit indicates
the status of internal write enable latch. When WEL bit
is “0”, the write enable latch is disabled, all write opera-
tions include write status register, write configuration reg-
ister, page program, sector erase, block and chip erase
operations are inhibited. When WEL bit is “1”, the write
enable latch is enabled. Then write operations are allowed.
The WEL bit is enabled by Write Enable (WREN) instruc-
tion. All write register, program and erase instructions
must be preceded by a WREN instruction every time.
The WEL bit can be disabled by Write Disable (WRDI)
instruction or automatically return to reset state after the
completion of a write instruction.
BP2, BP1, BP0 bits: The Block Protection (BP2
(Pm25LV040 only), BP1, BP0) bits are used to define
the portion of memory area to be protected. Refer to Table
5 and Table 6 Block Write Protection Bits Setting for
Pm25LV010/020 and Pm25LV040. When one of the
combination of BP2, BP1 and BP0 bits were set as “1”,
the relevant memory area is protected. Any program or
erase operation to that area will be prohibited. Especially,
the Chip Erase (CHIP_ER) instruction is executed only if
all the Block Protection Bits are set as “0”s.
If SCFG bit was enabled to support 1KB x4 sectores on
Sector 0, Sector 0’s protection status will respect SP0_x
in Configuration Register and ignore BPx bits status
whatever protection status.
Programmable Microelectronics Corp.
7
Issue Date: July, 2005, Rev: 1.2
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