JS48F4400PCZ00 datasheet(73/102 Pages) NUMONYX

73 / 102 page

November 2007

Datasheet

Order Number: 290701-18

Numonyx™ Wireless Flash Memory (W18)

13.1.4

Block Lock Status

Every block’s lock status can be read in read identifier mode. To enter this mode, issue

the Read Identifier command to the device. Subsequent reads at BBA + 02h will output

that block’s lock status. For example, to read the block lock status of block 10, the

address sent to the device should be 50002h (for a top-parameter device). The lowest

two data bits of the read data, DQ1 and DQ0, represent the lock status. DQ0 indicates

the block lock status. It is set by the Lock Block command and cleared by the Block

Unlock command. It is also set when entering the lock-down state. DQ1 indicates lock-

down status and is set by the Lock-Down command. The lock-down status bit cannot be

cleared by software–only by device reset or power-down. See Table 28.

13.1.5

Lock During Erase Suspend

Block lock configurations can be performed during an erase suspend operation by using

the standard locking command sequences to unlock, lock, or lock-down a block. This

feature is useful when another block requires immediate updating.

To change block locking during an erase operation, first write the Erase Suspend

command. After checking SR[6] to determine the erase operation has suspended, write

the desired lock command sequence to a block; the lock status will be changed. After

completing lock, unlock, read, or program operations, resume the erase operation with

the Erase Resume command (D0h).

If a block is locked or locked-down during a suspended erase of the same block, the

locking status bits change immediately. When the erase operation is resumed, it will

complete normally.

Locking operations cannot occur during program suspend. Appendix A, “Write State

Machine States” on page 86 shows valid commands during erase suspend.

13.1.6

Status Register Error Checking

Using nested locking or program command sequences during erase suspend can

introduce ambiguity into Status Register results.

Because locking changes require 2-cycle command sequences, for example, 60h

followed by 01h to lock a block, following the Configuration Setup command (60h) with

an invalid command produces a command sequence error (SR[5:4]=11b). If a Lock

Block command error occurs during erase suspend, the device sets SR[4] and SR[5] to

1 even after the erase is resumed. When erase is complete, possible errors during the

erase cannot be detected from the Status Register because of the previous locking

command error. A similar situation occurs if a program operation error is nested within

an erase suspend.

Table 28: Write Protection Truth Table

VPP

WP#

RST#

Write Protection

VIL

Device inaccessible

VIL

XVIH

Word program and block erase prohibited

XVIL

VIH

All lock-down blocks locked

XVIH

VIH

All lock-down blocks can be unlocked

JS48F4400PCZ00 Datasheet(PDF) 73 Page - Numonyx B.V

JS48F4400PCZ00 Datasheet(HTML) 73 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 99 100 ...More

Datasheet Download

Link URL