Numonyx™ StrataFlash® Embedded Memory (P33)
During a program suspend, deasserting CE# places the device in standby, reducing
active current. VPP must remain at its programming level, and WP# must remain
unchanged while in program suspend. If RST# is asserted, the device is reset.
11.3.5
11.3.6
Program Resume
The Resume command instructs the device to continue programming, and
automatically clears Status Register bits SR[7,2]. This command can be written to any
address. If error bits are set, the Status Register should be cleared before issuing the
next instruction. RST# must remain deasserted (see Figure 34, “Program Suspend/
Resume Flowchart” on page 70).
Program Protection
When VPP = VIL, absolute hardware write protection is provided for all device blocks. If
VPP is at or below VPPLK, programming operations halt and SR[3] is set indicating a VPP-
level error. Block lock registers are not affected by the voltage level on VPP; they may
still be programmed and read, even if VPP is less than VPPLK
.
Figure 30: Example VPP Supply Connections
VCC
VCC
VPP
VCC
VPP
VCC
VPP
PROT #
≤ 10K Ω
• Low-voltage Programming only
• Logic Control of Device Protection
• Factory Programming with VPP = VPPH
• Complete write/Erase Protection when VPP ≤ VPPLK
VCC
VCC
VCC
VCC
VPP
VPP=VPPH
VPP
• Low Voltage Programming Only
• Full Device Protection Unavailable
• Low Voltage and Factory Programming
11.4
Erase Operations
Flash erasing is performed on a block basis. An entire block is erased each time an
erase command sequence is issued, and only one block is erased at a time. When a
block is erased, all bits within that block read as logical ones. The following sections
describe block erase operations in detail.
11.4.1
Block Erase
Block erase operations are initiated by writing the Block Erase Setup command to the
address of the block to be erased (see Section 9.6, “Device Command Bus Cycles” on
page 44). Next, the Block Erase Confirm command is written to the address of the
block to be erased. If the device is placed in standby (CE# deasserted) during an erase
operation, the device completes the erase operation before entering standby. VPP must
be above VPPLK and the block must be unlocked (see Figure 37, “Block Erase Flowchart”
on page 73).
Datasheet
62
November 2007
Order Number: 314749-05
NUMONYX [ NUMONYX B.V ]
