JS28F640P30T85 datasheet(64/99 Pages) NUMONYX

64 / 99 page

P30

Datasheet

November 2007

Order Number: 306666-11

13.0

Security Modes

The device features security modes used to protect the information stored in the flash

memory array. The following sections describe each security mode in detail.

13.1

Block Locking

Individual instant block locking is used to protect user code and/or data within the flash

memory array. All blocks power up in a locked state to protect array data from being

altered during power transitions. Any block can be locked or unlocked with no latency.

Locked blocks cannot be programmed or erased; they can only be read.

Software-controlled security is implemented using the Block Lock and Block Unlock

commands. Hardware-controlled security can be implemented using the Block Lock-

Down command along with asserting WP#. Also, VPP data security can be used to

inhibit program and erase operations (see Section 11.6, “Program Protection” on

page 61 and Section 12.4, “Erase Protection” on page 63).

The P30 device also offers four pre-defined areas in the main array that can be

configured as One-Time Programmable (OTP) for the highest level of security. These

include the four 32 KB parameter blocks together as one and the three adjacent 128 KB

main blocks. This is available for top or bottom parameter devices.

13.1.1

Lock Block

To lock a block, issue the Lock Block Setup command. The next command must be the Lock Block command

issued to the desired block’s address (see Section 9.2, “Device Commands” on page 45 and

Figure 44, “Block Lock Operations Flowchart” on page 85). If the Set Read Configuration

configures the RCR instead.

Block lock and unlock operations are not affected by the voltage level on VPP. The block

lock bits may be modified and/or read even if VPP is at or below VPPLK.

13.1.2

Unlock Block

The Unlock Block command is used to unlock blocks (see Section 9.2, “Device

Commands” on page 45). Unlocked blocks can be read, programmed, and erased.

Unlocked blocks return to a locked state when the device is reset or powered down. If a

block is in a lock-down state, WP# must be deasserted before it can be unlocked (see

Figure 30, “Block Locking State Diagram” on page 65).

13.1.3

Lock-Down Block

A locked or unlocked block can be locked-down by writing the Lock-Down Block

command sequence (see Section 9.2, “Device Commands” on page 45). Blocks in a

lock-down state cannot be programmed or erased; they can only be read. However,

unlike locked blocks, their locked state cannot be changed by software commands

alone. A locked-down block can only be unlocked by issuing the Unlock Block command

with WP# deasserted. To return an unlocked block to locked-down state, a Lock-Down

command must be issued prior to changing WP# to VIL. Locked-down blocks revert to

the locked state upon reset or power up the device (see Figure 30, “Block Locking State

Diagram” on page 65).

JS28F640P30T85 bảng dữ liệu(PDF) 64 Page - Numonyx B.V

JS28F640P30T85 bảng dữ liệu(HTML) 64 Page - Numonyx B.V

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99

bảng dữ liệu tải về

Link URL