ST M28W640ECT, M28W640ECB User Manual

查询M28W640ECB10N1供应商

FEATURES SUMMARY

■ SUPPLY VOLTAGE

= 2.7V to 3.6V Core Power Supply

–V

DD

–V
–V

■ ACCESS TIME: 70, 85, 90,100ns

■ PROGRAMMING TIME:

– 10µ s typical
– Double Word Programming Option
– Quadruple Word Programming Option

■ COMMON FLASH INTERFACE

■ MEMORY BLOCKS

– Parameter Blocks (Top or Bott o m location)
– Main Blocks

■ BLOCK LOCKING

– All blocks locked at Power Up
– Any combination of blocks can be locked
–WP

■ SECURITY

– 128 bit user Programmable OTP cells
– 64 bit unique device identifier

■ AUTOMATIC STAND-BY MODE

■ PROGRAM and ERASE SUSPEND

■ 100,000 PROGRAM/ERASE CYCLES per

BLOCK

■ ELECTRONIC SIGNATURE

– Manufacturer Code: 20h
– Top Device Code, M28W640ECT: 8848h
– Bottom Device Code, M28W640ECB: 8849h

= 1.65V to 3.6V for Input/Output

DDQ

= 12V for fast Program (optional)

PP

for Block Lock-Down

M28W640ECT

M28W640ECB

64 Mbit (4Mb x16, Boot Block)

3V Supp l y Fl ash Mem ory

PRELIMINARY DATA

Figure 1. Packages

FBGA

TFBGA48 (ZB)

6.39 x 10.5mm

TSOP48 (N)

12 x 20mm

April 2003

This is preliminary information on a new product now in development or undergoing evaluation. Details are subject to change without notice.

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M28W640ECT, M28W640ECB

TABLE OF CONTENTS

SUMMARY DESCRIPTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Figure 2. Logic Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Table 1. Signal Names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Figure 3. TSOP Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Figure 4. TFBGA Connections (Top view through package). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Figure 5. Block Addresses. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Figure 6. Protection Register Memory Map. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

SIGNAL DESCRIPTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Address Inputs (A0-A21). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Data Input/Output (DQ0-DQ15). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Chip Enable (E). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Output Enable (G). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Write Enable (W). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Write Protect (WP). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Reset (RP). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

V

Supply Voltage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

DD

V

Supply Voltage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

DDQ

V

Program Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

PP

V

Ground. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

SS

BUS OPERATIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Read.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 0

Write.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Output Disable. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 0

Standby. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Automatic Standby. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Reset. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Read Electronic Signature Comma nd . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Table 2. Bus Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

COMMAND INTERFACE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Read Memory Array Command. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11

Read Status Register Command. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11

Read Electronic Signature Comma nd . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Table 3. Command Codes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Read CFI Query Command. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Block Erase Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Program Command. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Double Word Program Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Clear Status Register Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Program/Erase Suspend Comm and . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Program/Erase Resume Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Protection Register Program Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

2/55

M28W640ECT, M28W640ECB

Block Lock-Down Command. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

Table 4. Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Table 5. Read Electronic Signature. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Table 6. Read Block Lock Signature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15

Table 7. Read Protection Register and Lock Register . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Table 8. Program, Erase Times and Program/Er ase Endu rance Cycles . . . . . . . . . . . . . . . . . . . . 16

BLOCK LOCKING. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Locked State . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Unlocked State . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Lock-Down State. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Reading a Block’s Lock Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Locking Operations During Erase Suspend . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Table 9. Block Lock Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Table 10. Protection Status . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

STATUS REGISTER. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Program/Erase Controller Status (Bit 7) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19

Erase Suspend Status (Bit 6) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Erase Status (Bit 5). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Program Status (Bit 4). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

V

Status (Bit 3). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

PP

Program Suspend Status (Bit 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Block Protection Status (Bit 1). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Reserved (Bit 0). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Table 11. Status Register Bits. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

MAXIMUM RATING. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Table 12. Absolute Maximum Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

DC and AC PARAMETERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 2

Table 13. Operating and AC Measurement Conditions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Figure 7. AC Measurement I/O Waveform . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22

Figure 8. AC Measurement Load Circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Table 14. Capacitance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Table 15. DC Characteristics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Figure 9. Read AC Waveforms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Table 16. Read AC Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Figure 10. Write AC Waveforms, Write Enable Controlled . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Table 17. Write AC Characteristics, Write Enable Controlled . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Figure 11. Write AC Waveforms, Chip Enable Controlled . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

Table 18. Write AC Characteristics, Chip Enable Controlled . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

Figure 12. Power-Up and Reset AC Waveforms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

Table 19. Power-Up and Reset AC Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

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M28W640ECT, M28W640ECB

PACKAGE MECHANICAL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

Figure 13. TSOP48 - 48 lead Plastic Thin Small Outline, 12 x 20mm, Package Outline . . . . . . . . 30

Table 20. TSOP48 - 48 lead Plastic Thin Small Outline, 12 x 20mm, Package Mechanical Data . 30
Figure 14. TFBGA48 6.39x10.5m m - 8x6 ball array, 0.75mm pitch, Bottom View Package Out line31
Table 21. TFBGA48 6.39x10.5mm - 8x6 ball array, 0.75mm pitch, Package Mechanical Data . . . 31

Figure 15. TFBGA48 Daisy Chain - Package Connections (Top view through package) . . . . . . . . 32

Figure 16. TFBGA48 Daisy Chain - PCB Connections proposal (Top view through package). . . . 32

PART NUMBERING . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Table 22. Ordering Information Scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33

Table 23. Daisy Chain Ordering Scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

APPENDIX A. BLOCK ADDRESS TABLES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Table 24. Top Boot Block Addresses, M28W640ECT. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Table 25. Bottom Boot Block Addresses, M28W640ECB. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

APPENDIX B. COMMON FLASH INTERFACE (CFI) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Table 26. Query Structure Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39

Table 27. CFI Query Identification String . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39

Table 28. CFI Query System Interface Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

Table 29. Device Geometry Definition. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41

Table 30. Primary Algorithm-Specific Extended Query Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

Table 31. Security Code Area . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

APPENDIX C. FLOWCHARTS AND PSEUDO CODES. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

Figure 17. Program Flowchart and Pseudo Code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

Figure 18. Double Word Program Flowchart and Pseudo Code . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

Figure 19. Quadruple Word Program Flowchart and Pseudo Code . . . . . . . . . . . . . . . . . . . . . . . . 46

Figure 20. Program Suspend & Resume Flowchart and Pseudo Code . . . . . . . . . . . . . . . . . . . . . 47

Figure 21. Erase Flowchart and Pseudo Code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

Figure 22. Erase Suspend & Resume Flowchart and Pseudo Code. . . . . . . . . . . . . . . . . . . . . . . . 49

Figure 23. Locking Operations Flowchart and Pseudo Code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

APPENDIX D. COMMAND INTERFACE AND PROGRAM/ERASE CONTROLLER STATE . . . . . . . 52

Table 32. Write State Machine Current/Next, sheet 1 of 2.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

Table 33. Write State Machine Current/Next, sheet 2 of 2.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

REVISION HISTORY. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

Table 34. Document Revision History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .54

4/55

SUMMARY DESCRIPTION

The M28W640EC is a 64 Mbit (4 Mbit x 16) non­volatile Flash memory that can b e erased electri­cally at block level and programmed in-s ystem on
a Word-by-Word basis using a 2.7V to 3.6V V
supply for the circuitry and a 1.65V to 3.6V V

DD

DDQ

supply for the Input/Output pins. An optional 12V
V

power supply is provided to speed up custom-

PP

er programming.
The device features an asymmetrical blocked ar-

chitecture. The M28W640EC ha s an array of 135
blocks: 8 Parameter Blocks of 4 KWord and 127
Main Blocks of 32 KWord. M28W640ECT has the
Parameter Blocks at the top of the memory ad­dress space while the M28W640ECB locates the
Parameter Blocks starting from the bottom. The
memory maps are shown in Figure 5, Block Ad­dresses.

The M28W640EC features an instant, individual
block locking scheme that allo ws any block to be
locked or unlocked with no latency, enabling in­stant code and data protection. All blocks have
three levels of protection. They can be locked and
locked-down individually preventing any acciden­tal programming or erasure. There is an additional
hardware protection against program and erase.
When V

PP

≤ V

all blocks are protected against

PPLK

program or erase. All blocks are locked at Power
Up.

Each block can be erased separately. Erase can
be suspended in order to perform either read or
program in any other block and then resumed.
Program can be s uspended to read data in any
other block and then resumed. Each block can be
programmed and erased over 100,000 cycles.

The device includes a 192 b it Protection Register
to increase th e pr o tection of a system design. The
Protection Register is divided into a 64 bit segment
and a 128 bit segment. The 64 bi t segment con­tains a unique device number written by ST, while
the second one is one-time-programmable by the
user. The user programmable segment can be
permanently protected. Figure 6, shows the Pro­tection Register Memory Map.

Program and Erase command s are written to the
Command Interface of the memory. An on-chip
Program/Erase Controller takes care of the tim­ings necessary for program and erase operations.
The end of a program or erase operation can be
detected and any error conditions identified. The
command set required to control the memory is
consistent with JEDEC standards.

M28W640ECT, M28W640ECB

The memory is of fered in TSOP48 (12 X 20mm)
and TFBGA48 (6.39 x 10.5mm, 0.75mm pitch)
packages and is supplied with all the bits erased

(set to ’1’).

Figure 2. Logic Diagram

V

V

DD

DDQVPP

22

A0-A21

W

E

G

RP

WP

M28W640ECT
M28W640ECB

V

SS

Table 1. Signal Names

A0-A21 Address Inputs
DQ0-DQ15 Data Input/Output
E
G
W
RP
WP
V

DD

V

DDQ

V

PP

V

SS

NC Not Connected Internally

Chip Enable
Output Enable
Write Enable
Reset
Write Protect
Core Power Supply
Power Supply for

Input/Output
Optional Supply Voltage for

Fast Program & Erase
Ground

16

DQ0-DQ15

AI04378b

5/55

M28W640ECT, M28W640ECB

Figure 3. TSOP Connections

A15
A14
A13
A12
A11

1

48

A16
V

DDQ

V

SS

DQ15
DQ7

A10 DQ14

37
36

DQ6
DQ13
DQ5
DQ12
DQ4
V

DD

DQ11
DQ3
DQ10
DQ2
DQ9
DQ1
DQ8
DQ0
G
V

SS

E
A0

A21
A20

RP

V

PP

WP
A19
A18
A17

A9
A8

W

A7
A6
A5
A4
A3
A2
A1

12

M28W640ECT
M28W640ECB

13

24 25

AI04379b

6/55

Figure 4. TFBGA Connections (Top view through package)

M28W640ECT, M28W640ECB

87654321

A

B

C

D

E

F

DDQ

SS

DQ7V

A8A11A13

DQ13

PP

RP A18

A21

DQ11

DQ12

DQ4

WP A19

A20

DQ2

DD

A7V

A5A17WA10A14

DQ0DQ9DQ3DQ6DQ15V

DQ1DQ10V

A4

A2

A1A3A6A9A12A15

A0EDQ8DQ5DQ14A16

V

SS

G

AI04380

7/55

M28W640ECT, M28W640ECB

Figure 5. Block Addresses

M28W640ECT

Top Boot Block Addresses

3FFFFF

3FF000

3F8FFF

3F8000

3F7FFF

3F0000

00FFFF

008000

007FFF

000000

Note: A l so see Appe ndi x A, Tables 24 and 25 for a full l isting of the Bl ock Address es.

4 KWords

Total of 8

4 KWord Blocks

4 KWords

32 KWords

Total of 127

32 KWord Blocks

32 KWords

32 KWords

Bottom Boot Block Addresses

3FFFFF

3F8000

3F7FFF

3F0000

00FFFF

008000

007FFF

007000

000FFF

000000

M28W640ECB

32 KWords

32 KWords

Total of 127

32 KWord Blocks

32 KWords

4 KWords

Total of 8

4 KWord Blocks

4 KWords

AI04386b

Figure 6. Prot ect i on Register Me m o ry Map

PROTECTION REGISTER

8Ch

User Programmable OTP

85h
84h

81h
80h

Unique device number

Protection Register Lock 1 0

AI05520b

8/55

SIGNAL DESCRIPTIONS

See Figure 2 Logic Diagram and Table 1,Signal
Names, for a brief overview of the signals connect­ed to this device.

Address Inputs (A0-A21). The Address Inputs
select the cells i n the memory array to a ccess dur­ing Bus Read operations. During Bus Write opera­tions they control the commands sent to the
Command Interface of the internal state machine.

Data Input/Output (DQ0-DQ15). The Data I/O
outputs the data stored at the selected address
during a Bus Read operation or inputs a command
or the data to be programmed durin g a Write Bus
operation.

Chip Enable (E

). The Chip Enable input acti-

vates the memory control logic, input buffers, de­coders and sense amplifiers. When Chip Enable is

and Reset is at VIH the device is in active

at V

IL

mode. When Chi p E nable i s at V

the memory is

IH

deselected, the outputs are high impedan ce and
the power consumption is reduced to the stand-by
level.

Output Enable (G

). The Output Enable controls

data outputs during the Bus Read operation of the
memory.

Write Enable (W

). The Write Enable controls the

Bus Write operation of the memory’s Command
Interface. The data and address inputs are latched
on the rising edge of Chip Enable, E, or Write En­able, W

Write Protect (WP

, whichever occurs first.

). Write Protect is an input
that gives an additional hardware protection for
each block. When Write Protect is at V

, the Loc k-

IL

Down is enabled and the prote ction status of t he
block cannot be changed. When Write Protect is at

, the Lock-Down is disabled and the block can

V

IH

be locked or unlocked. (refer to Table 7, Read Pro­tection Register and Protection Register Lock).

Reset (RP

ware reset of the memory. W hen Reset is at V

). The Reset input provides a hard-

IL

the memory is in reset mode: the outputs are high
impedance and the current consumption is mini­mized. After Reset all blocks are in the Locked

M28W640ECT, M28W640ECB

state. When Reset is at V
operation. Exiting reset mode the device enters
read array mode, but a negative transition of Chip
Enable or a change of the addres s is required t o
ensure valid data outputs.

Supply Voltage. VDD provides the power

V

DD

supply to the internal core of the memory device.
It is the main power supply for all operations
(Read, Program and Erase).

Su pp ly V olt ag e . V

V

DDQ

power supply to the I/O pins a nd ena bles all Ou t­puts to be powered independently from V
can be tied to VDD or can use a separate supply.

Program Supply Voltage. VPP is both a

V

PP

control input and a power supply pin. The two
functions are selected by the voltage range ap­plied to the pin. The Supply Voltage V
Program Supply Voltage V
any order.

If V

is kept in a low voltage range (0V to 3.6V)

PP

V

is seen as a control input. In this case a volt-

PP

age lower than V

PPLK

against program or erase, whi le V
ables these functions (see Table 15, DC Charac­teristics for the relevant values). V
sampled at the beginning of a program or erase; a
change in its value after the operation has started
does not have any effect on Program or Erase,
however for Double or Q uadruple Word Program
the results are uncertain.

If V

is in the range 11.4V to 12.6V it acts as a

PP

power supply pin. In this condition V
stable until the Program/Erase algorit hm is com­pleted (see Table 17 and 18).

Ground. VSS is the reference for all voltage

V

SS

measurements.

Note: Each device in a system should have
V

DD, VDDQ

pacitor close to the pin. See Figure 8, AC Mea-

,

and VPP decoupled wi th a 0.1 µF ca-

surement Load Circu it. The PCB trace widths
should be sufficient to carry the required V
program and erase currents.

, the device is in normal

IH

provides the

DDQ

can be applied in

PP

gives an absolute protection

PP

DD

and the

DD

> V

is only

PP

must be

PP

. V

PP1

DDQ

en-

PP

9/55

M28W640ECT, M28W640ECB

BUS OPERATIONS

There are six standard bus operations that control
the device. These are Bus Read, Bus Wri te, Out­put Disable, Standby, Automatic Standby and Re­set. See Table 2, Bus Operations, for a summary.

Typically glitches of less than 5ns on Chip Enable
or Write Enable are ignored by the memory and do
not affect bus operations.

Read. Read Bus operations are used to output
the contents of the Memory Array, the Electronic
Signature, the Status Register and the Common
Flash Interface. Both Chip Enable and Output En­able must be at V
eration. The Chip Enable in put should be us ed to
enable the device. Out put E nable shoul d be used
to gate data onto the output. The data read de­pends on the previous command written to the
memory (see Command Interface section). See
Figure 9, Read Mode AC Wa veforms, and Table
16, Read AC Characteristics, for details of when
the output becomes valid.

Read mode is the default state of the device when
exiting Reset or after power-up.

Write. Bus Write operations write Commands to
the memory or latch Input Data to be programmed.
A write operation is initiated when Chip Enable
and Write Enable are at V
V

. Commands, Input Data and Addresses are

IH

latched on the rising edge of Write Enable or Chip
Enable, whichever occurs first.

in order to perform a read op-

IL

with Output Enable at

IL

See Figures 10 and 11, Write AC Waveforms, and
Tables 17 and 18, Write AC Characteristics, for
details of the timing requirements.

Output Disa bl e . The data outputs are high im­pedance when the Output Enable is at V

.

IH

Standby. Stan dby disables most of the inte rnal
circuitry allowing a substantial reduction of the cur­rent consumption. The memory is in stand-by
when Chip Enable is at V

and the device is in

IH

read mode. The power consumption is reduced to
the stand-by level and the o utputs are set to high
impedance, independently from the Output Enable
or Write Enable inputs. If Chip Enable switches to
V

during a program or erase operation, t he de-

IH

vice enters Standby mode when finished.
Automatic Standby. Automatic Standby pro-

vides a low power consumption state during Read
mode. Following a read operation, the device en­ters Automatic Standby after 150ns of bus inactiv­ity even if Chip Enable is Low, V
current is reduced to I

. The data I nputs/Out-

DD1

, and the supply

IL

puts will still output data if a bus Read operation is
in progress.

Reset. During Reset mode when Output Enable
is Low, V

, the memory is deselected and the out-

IL

puts are high impedance. The memory is in Reset
mode when Reset is at V

. The power consump-

IL

tion is reduced to the Standby level, independently
from the Chip Enable, Output Enable or Write En­able inputs. If Reset is pulled to V

during a Pro-

SS

gram or Erase, this operation is aborted and the
memory content is no longer valid.

Table 2. Bus Operations

Operation E G W RP WP

Bus Read
Bus Write
Output Disable
Standby
Reset X X X

Note: X = VIL or VIH, V

10/55

V
V
V
V

= 12V ± 5%.

PPH

IL

IL

IL

IH

V

IL

V

IH

V

IH

XX

V

IH

V

IL

V

IH

V

IH

V

IH

V

IH

V

IH

V

IL

V

PP

X Don’t Care Data Output

V

X
X Don’t Care Hi-Z
X Don’t Care Hi-Z
X Don’t Care Hi-Z

DD

or V

PPH

DQ0-DQ15

Data Input

COMMAND INTERFACE

All Bus Write operations t o the me mory are in ter­preted by the Command Interface. Commands
consist of one or more sequential Bus Write oper­ations. An internal Program/Erase Controller han­dles all timings and verifies the correct execution
of the Program and Erase commands. The Pro­gram/Erase Controller provides a S tatus Register
whose output may be read at any time during, to
monitor the progress of the operation, or the P ro­gram/Erase states. See Table 3, Command
Codes, for a summary o f the c ommands and see
Appendix 22, Table 32, Write State Machine Cur­rent/Next, for a summa ry of the Command Inter­face.

The Command Interface is reset to Read mode
when power is first applied, when exiting from Re­set or whenever V

is lower than V

DD

LKO

. Com­mand sequences must be followed exactly. Any
invalid combination of commands will reset the de­vice to Read mode. Refer to Table 4, Commands,
in conjunction with the text descriptions below.

Read Memory Array Command

The Read command returns the memory to its
Read mode. One Bus Write cycle is required to is­sue the Read Memory Array command and return
the memory to Read mode. Subsequ ent read op­erations will read the addressed locat ion and out­put the data. When a device Reset occurs, the
memory defaults to Read mode.

Read Status Register Command

The Status Register indicates when a program or
erase operation is complete and the success or
failure of the operation itself. Issue a Read Status

Register command to rea d the Status Register’s
contents. Subsequent Bus Read op erations read
the Status Register at any address, u ntil another
command is issued. See Table 11, Status Register
Bits, for details on the definitions of the bits.

The Read Status Register command m ay be is­sued at any time, even during a Program/Erase
operation. Any Read attempt during a Program/
Erase operation will automatically output the con­tent of the Status Register.

Read Electronic Signature Command

The Read Electronic Signature command reads
the Manufacturer and Device Codes and the Block
Locking Status, or the Protection Register.

The Read Electronic Signature command consists
of one write cycle, a subsequent read will output
the Manufacturer Code, the Device Code, the
Block Lock and Lock-Down Status, or the Protec­tion and Lock Register. See Tables 5, 6 and 7 for
the valid address.

M28W640ECT, M28W640ECB

Table 3. Command Codes

Hex Code Command

01h Block Lock confirm

10h Program
20h Erase

2Fh Block Lock-Down confirm

30h
40h Program

50h Clear Status Register
56h

60h

70h Read Status Register
90h Read Electronic Signature
98h Read CFI Query
B0h Program/Erase Suspend

C0h Protection Register Program

D0h

FFh Read Memory Array

Read CFI Query Command

The Read Query Command is used to read dat a
from the Common Flash Interface (CFI) Me mory
Area, allowing programming equi pment or appli­cations to automatically match their interface to
the characteristics of the device. One Bus Write
cycle is required to issue the Read Query Com­mand. Once the command is issued subsequent
Bus Read operations read from the Common
Flash Interface Memory Area. See Appendix B,
Common Flash Inte rface, Tables 26, 27, 28, 29,
30 and 31 for details on the information contained
in the Common Flash Interface memory area.

Block Erase Command

The Block Erase com mand can be used to erase
a block. It sets all the bits within the selected block
to ’1’. All previous d ata in th e block is lost. If th e
block is protected then the Erase operation will
abort, the data in the block will not be changed and
the Status Register will output the error.

Two Bus Write cycles are required to issue the
command.

■ The first bus cycle sets up the Erase command.

Double Word Program

Quadruple Word Program
Block Lock, Block Unlock, Block Lock-

Down

Program/Erase Resume, Block Unlock
confirm

11/55

M28W640ECT, M28W640ECB

■ The second latches the block address in the

internal state machine and starts the Program/
Erase Controller.

If the second bus cycle is not Write Erase Confirm
(D0h), Status Register bits b4 and b5 a re s et and
the command aborts.

Erase aborts if Reset turns to V

. As data integrity

IL

cannot be guaranteed when the Erase operation is
aborted, the block must be erased again.

During Erase operations the memory will accept
the Read Status Re gister com mand and the P ro­gram/Erase Suspend command, all other com­mands will be ignored. Typical Erase times are
given in Table 8, Program, Erase Times and P ro­gram/Erase Endurance Cycles.

See Appendix C, Figure 21 , Erase Flowchart and
Pseudo Code, for a suggested flowchart for using
the Erase command.

Program Command

The memory array can be programmed word-by­word. Two bus write cycles are required to issue
the Program Command.

■ The first bus cycle sets up the Program

command.

■ The second latches the Address and the Data to

be written and starts the Program/Erase
Controller.

During Program operations the memory will ac­cept the Read Status Register command and the
Program/Erase Suspend command. Typical Pro­gram times are g iven in Tab le 8, P rogram, E rase
Times and Program/Erase Endurance Cycles.

Programming aborts if Reset goe s to V

. As data

IL

integrity cannot be guaranteed when the program
operation is aborted, the block containing the
memory location must be erased and repro­grammed.

See Appendix C, Figure 17, Program Flowchart
and Pseudo Code, for the f lowchart for using the
Program command.

Double Word Program Command

This feature is offered to improve the programming
throughput, writing a page of two adjacent words
in parallel.The two words m ust differ only for the
address A0. Programm ing should not be at t emp t­ed when V

is not at V

PP

PPH

.

Three bus write cycles are necessary to issue the
Double Word Program command.

■ The first bus cycle sets up the Double Word

Program Command.

■ The second bus cycle latches the Address and

the Data of the first word to be written.

■ The third bus cycle latches the Address and the

Data of the second word to be written and starts
the Program/Erase Controller.

Read operations output the Status Register con­tent after the programming has s tarted. Program­ming aborts if Reset goes to V

. As data integrity

IL

cannot be guaranteed when the program opera­tion is aborted, the block containing the memory
location must be erased and reprogrammed.

See Appendix C, Figure 18, Double Word Pro­gram Flowchart and Pseudo Code, for the flow­chart for using the Double Word Program
command.

Quadruple Word Program Command

This feature is offered to improve the programming
throughput, writing a page of four adjacent words
in parallel.The four words must differ only for the
addresses A0 and A1. Programming should not be
attempted when V

is not at V

PP

PPH

.

Five bus write cycles are necessary to issue the
Quadruple Word Program command.

■ The first bus cycle sets up the Quadruple Word

Program Command.

■ The second bus cycle latches the Address and

the Data of the first word to be written.

■ The third bus cycle latches the Address and the

Data of the second word to be written.

■ The fourth bus cycle latches the Address and

the Data of the third word to be written.

■ The fifth bus cycl e latches the Addres s and th e

Data of the fourth word to be written and starts
the Program/Erase Controller.

Read operations output the Status Register con­tent after the programming has s tarted. Program­ming aborts if Reset goes to V

. As data integrity

IL

cannot be guaranteed when the program opera­tion is aborted, the block containing the memory
location must be erased and reprogrammed.

See Appendix C, Figure 19, Quadruple Word Pro­gram Flowchart and Pseudo Code, for the flow­chart for using the Quadruple Word Program
command.

Clear Status Register Command

The Clear Status Register comm and c an b e us ed
to reset bits 1, 3, 4 and 5 in the Status Register to

‘0’. One bus write cycle is required to issue the
Clear Status Register command.

The bits in the Status Register do not automatical­ly return to ‘0’ when a new Program or Erase com­mand is issued. The error bits in the Status
Register should be cleared before attempting a
new Program or Erase command.

Program/Erase Suspend Command

The Program/Erase Suspend command is used to
pause a Program or Erase operation. One bus
write cycle is required to issue the Program/Erase
command and pau se the Prog ram/Erase control­ler.

12/55

M28W640ECT, M28W640ECB

During Program/Erase Suspend the Command In­terface will accept the Program/Erase Resume,
Read Array, Read Status Register, Read Electron­ic Signature and Read CFI Query commands. Ad­ditionally, if the suspend operation was Erase then
the Program, Double Word Program, Quadruple
Word Program, Block Lock, Block Lock -Down or
Protection Program commands will also be ac­cepted. The block being erased may be protected
by issuing the Block Protect, Block Lock or Protec­tion Program commands. When the Program/
Erase Resume com mand is issued the operation
will complete. Only the blocks not being erased
may be read or programmed correctly.

During a Program/Erase Suspend, the device can
be placed in a pseudo-standby mode by taking
Chip Ena ble to V
Reset turns to V

. Program/Erase is aborted if

IH

.

IL

See Appendix C, Figure 20 , Program Suspend &
Resume Flowchart and Pseudo Code, and Figure
22, Erase Suspend & Resume Flowchart and
Pseudo Code for flowcharts for using the Program/
Erase Suspend command.

Program/Erase Resume Command

The Program/Erase Resume command can be
used to restart the Program/Erase Controller after
a Program/Erase Suspend o peration has paused
it. One Bus Write cycle is required to issue the
command. Once the command is issued subse­quent Bus Read operations read the Status Reg­ister.

See Appendix C, Figure 20 , Program Suspend &
Resume Flowchart and Pseudo Code, and Figure
22, Erase Suspend & Resume Flowchart and
Pseudo Code for flowcharts for using the Program/
Erase Resume command.

Protectio n Register Program Command

The Protection Register Program command is
used to Program the 128 bit user O ne-Time-Pro­grammable (OTP) segment of the Protection Reg­ister. The segment is programmed 16 bits at a
time. When shipped all bits in the segment are set

to ‘1’. The user can only program the bits to ‘0’.
Two write cycles are required to issue the Protec-

tion Register Program command.

■ The first bus cycle sets up the Protection

Register Program command.

■ The second latches the Address and the Data to

be written to the Protection Register and starts
the Program/Erase Controller.

Read operations output the Status Register con­tent after the programming has started.

The segment can be protected by programming bit
1 of the Protection Lock Register (see F igure 6,
Protection Register Memory Map). Attempting to
program a previously prot ected Protection Regis-

ter will result in a Status Register error. The pro­tection of the Protection Register is not reversible.

The Protection Register Program cannot be sus­pended.

Block Lock Command

The Block Lock command is used to lock a block
and prevent Program or Erase operations from
changing the data in it. All blocks are locked at
power-up or reset.

Two Bus Write cycles are required to issue the
Block Lock command.

■ The first bus cycle sets up the Block Lock

command.

■ The second Bus Write cycle latc hes the block

address.

The lock status can be monitored for each block
using the Read Electronic Signature command.
Table. 10 shows the protection status after issuing
a Block Lock command.

The Block Lock bits are vo latile, once set they re­main set until a hardware reset or power-down/
power-up. They are cleared by a Blocks Unlock
command. Refer to the section, Block Locking, for
a detailed explanation.

Block Unlock Command

The Blocks Unlock command i s used to unlock a
block, allowing the block to be programmed or
erased. Two Bus Write cycles are requ ired to is­sue the Blocks Unlock command.

■ The first bus cycle sets up the Block Unlock

command.

■ The second Bus Write cycle latc hes the block

address.

The lock status can be monitored for each block
using the Read Electronic Signature command.
Table. 10 shows the protection status after issuing
a Block Unlock command. Refer to the section,
Block Locking, for a detailed explanation.

Block Lock-Down Command

A locked block cannot be Programmed or Erased,
or have its protection status changed when WP
low, V

. When WP is high, V

IL

the Lock-Down

IH,

is

function is disabled and the locked blocks can be
individually unlocked by the Block Unlock com­mand.

Two Bus Write cycles are required to issue the
Block Lock-Down command.

■ The first bus cycle sets up the Block Lock

command.

■ The second Bus Write cycle latc hes the block

address.

The lock status can be monitored for each block
using the Read Electronic Signature command.
Locked-Down blocks revert to the locked (and not

13/55

M28W640ECT, M28W640ECB

locked-down) state when the device is reset on
power-down. Table. 10 sho ws the protection sta-

Refer to the section, Block Locking, for a detailed
explanation.

tus after issuing a Block Lock-Down command.

Table 4. Commands

Bus Write Operations

Commands

Read Memory
Array

Read Status
Register

Read Electronic
Signature

Read CFI Query 1+ Write X 98h Read QA QD
Erase 2 Write X 20h Write BA D0h

Program 2 Write X

Double Word
Program

Quadruple Word
Program

Clear Status
Register

Program/Erase
Suspend

Program/Erase
Resume

Block Loc k 2 Write X 60h Write
Block Unlock 2 Write X 60h Write
Block Loc k-Down 2 Write X 60h Write
Protection

Register Program

Note: 1. X = Don’t C are, RA=Rea d Addre ss, RD =Read D ata, SRD =Stat us Regis ter Da ta, ID =Identif ier (Ma nufact ure and Devic e Code),

(3)

(4)

QA=Query Address, QD=Query Data, BA=Block Address, PA=Program Address, PD=Program Data, PRA=Protection Register Ad­dress, PRD=Protection Register Data.

2. The s i gnature addresses are li st ed in Tables 5, 6 and 7.

3. Program Addres ses 1 and 2 must be consecuti ve Addresses differing only for A0.

4. Program Addres ses 1,2,3 and 4 m ust be consec utive Addr esses differi ng only for A 0 and A1.

5. To be c haracteriz ed.

1+ Write X FFh

1+ Write X 70h Read X SRD

1+ Write X 90h Read

1st Cycle 2nd Cycle 3rd Cycle 4th Cycle 5th Cycle

Cycles

Op. Add Data Op. Add Data Op. Add Data Op. Add Data Op. Add Data

RA RD

Read

(2)

IDh

SA

40h or

Write P A PD

10h

3 Write X 30h Write PA1 PD1 Write PA2 PD2

5 Write X

1 Write X 50h

1Write X B0h

1Write X D0h

(5)

Write PA1 PD1 Write PA2 PD2 Write PA3 PD3 Write PA4 PD4

56h

01h

BA
BA D0h
BA 2Fh

2 Write X C0h Write

PRA

PRD

Table 5. Read Electronic Signature

Code Device E G W A0 A1 A2-A7 A8-A21 DQ0-DQ7 DQ8-DQ15

Manufacture
Code

M28W640ECT

Device Code

M28W640ECB

Note: RP = VIH.

14/55

VILV

V

IL

V

VILV

IL

V

VILV

IL

V

IH

IHVIH

IHVIH

V

IL

V
V

0 Don’t Care 20h 00h

IL

0 Don’t Care 48h 88h

IL

0 Don’t Care 49h 88h

IL

M28W640ECT, M28W640ECB

Table 6. Read Block Lock Signature

Block Status E G W A0 A1 A2-A7 A8-A11 A12-A21 DQ0 DQ1 DQ2-DQ15

Locked Block
Unlocked Block
Locked-Down

Block

Note: 1. A Locked-Down Blo ck can be lock ed "DQ0 = 1" or unlocked "DQ0 = 0" ; s ee B l ock Locking section.

Table 7. Read Protection Register and Lock Register

Word E

Lock

Unique ID 0
Unique ID 1
Unique ID 2
Unique ID 3
OTP 0
OTP 1
OTP 2
OTP 3
OTP 4
OTP 5
OTP 6
OTP 7

V

ILVILVIHVILVIH

V

ILVILVIHVILVIH

V

ILVILVIHVILVIH

0 Don’t Care Block Address 1 0 00h
0 Don’t Care Block Address 0 0 00h

0 Don’t Care Block Address

X

(1)

1 00h

G W A0-A7 A8-A21 DQ0 DQ1 DQ2 DQ3-DQ7 DQ8-DQ15

V

ILVILVIH

V

ILVILVIH

V

ILVILVIH

V

ILVILVIH

V

ILVILVIH

V

ILVILVIH

V

ILVILVIH

V

ILVILVIH

V

ILVILVIH

V

ILVILVIH

V

ILVILVIH

V

ILVILVIH

V

ILVILVIH

80h Don’t Care 0

81h Don’t Care ID data ID data ID data ID data ID data
82h Don’t Care ID data ID data ID data ID data ID data
83h Don’t Care ID data ID data ID data ID data ID data
84h Don’t Care ID data ID data ID data ID data ID data
85h Don’t Care OTP data OTP data OTP data OTP data OTP data
86h Don’t Care OTP data OTP data OTP data OTP data OTP data
87h Don’t Care OTP data OTP data OTP data OTP data OTP data
88h Don’t Care OTP data OTP data OTP data OTP data OTP data

89h Don’t Care OTP data OTP data OTP data OTP data OTP data
8Ah Don’t Care OTP data OTP data OTP data OTP data OTP data
8Bh Don’t Care OTP data OTP data OTP data OTP data OTP data
8Ch Don’t Care OTP data OTP data OTP data OTP data OTP data

OTP Prot.

data

0 00h 00h

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M28W640ECT, M28W640ECB

Table 8. Program , Erase Times and Program/Erase Endurance Cycl es

Parameter Test Conditions

V

Word Program

Double Word Program
Quadruple Word Program

Main Block Program

Parameter Block Program

Main Block Erase

Parameter Block Erase

Program/Erase Cycles (per Block) 100,000 cycles

Note: 1. Typical time to program a Main or Parameter Block using the Double Word Program and the Quadruple Word Program commands

respectively.

= V

PP

V

= 12V ±5%

PP

V

= 12V ±5%

PP

V

= 12V ±5%

PP

= V

V

PP

= 12V ±5%

V

PP

= V

V

PP

= 12V ±5%

V

PP

= V

V

PP

V

= 12V ±5%

PP

V

= V

PP

DD

DD

DD

DD

DD

Min Typ Max

M28W640EC

10 200 µs
10 200 µs
10 200 µs

0.16/0.08

0.02/0.01

(1)

0.32 5 s

(1)

0.04 4 s
110s
110s

0.4 10 s

0.4 10 s

5s

4s

Unit

BLOCK LOCKING

The M28W640EC features an instant, individual
block locking scheme that allo ws any block to be
locked or unlocked with no latency. This locking
scheme has three levels of protection.

■ Lock/Unlock - this first level allows software-

only control of block locking.

■ Lock-Down - this second level requires

hardware interaction before locking can be
changed.

■ V

PP

≤ V

- the third level offers a complete

PPLK

hardware protection against program and erase
on all blocks.

The protection status of each block can be set to
Locked, Unlocked, and Lock-Down. Table 10, de­fines all of the possible protection states (WP
DQ1, DQ0), and Appendi x C, Figure 23, shows a
flowchart for the locking operations.

Reading a Block’s Lock Status

The lock status of every block can be read in the
Read Electronic Signature mode of the device. To
enter this mode write 90h t o the device. Subse­quent reads at the addres s specified in Table 6,
will output the pr otection sta tus of that bloc k. The
lock status is represented by DQ0 and DQ 1. DQ0
indicates the Block Lock/Unlock status and i s set
by the Lock comm and and cleared by the Unlock

command. It is also automatically set when enter­ing Lock-Down. DQ1 indicates the Lock-Down sta­tus and is set by the Lock-Down command. It
cannot be cleared by software, only by a hardware
reset or power-down.

The following sections explain the operation of the
locking system.

Locked State

The default status of all blocks on power-up or af­ter a hardware reset is L ocked (states (0,0,1) or
(1,0,1)). Locked blocks are fully protected from
any program or erase. Any program or erase oper­ations attempted on a locked block will return an
error in the Status Register. The Status of a
Locked block can be changed to Unlocked or
Lock-Down using the appropriate software com-

,

mands. An Unlocked block can be Locked by issu­ing the Lock command.

Unlocked State

Unlocked blocks (states (0,0,0), (1,0,0) (1,1,0)),
can be programmed or erased. All unlocked
blocks return to the Locked state after a hardware
reset or when the device is powered-down. The
status of an unlocked block can be changed to
Locked or Locked-Down using the appropriate
software commands. A locked block can be un­locked by issuing the Unlock command.

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M28W640ECT, M28W640ECB

Lock-Down State

Blocks that are Locked-Down (state (0,1,x))are
protected from program and erase operations (as
for Locked blocks) but th eir protect ion status can­not be changed using software comma nds alone.
A Locked or Unlocked block can be Locked-Down
by issuing the Lock-Down command. Locked­Down blocks revert to the Locked state when the
device is reset or powered-down.

The Lock-Down function is depen dent on the WP
input pin. When WP=0 (VIL), the blocks in the
Lock-Down state (0,1,x) are protected from pro­gram, erase and protection status changes. When

=1 (VIH) the Lock-Down function is disabled

WP
(1,1,1) and Locked-Down blocks can be ind ividu­ally unlocked to the (1,1,0) state by issuing the
software command, where they can be erased and
programmed. These blocks can then be relocked
(1,1,1) and unlocked (1,1,0) as desired while WP
remains high. When WP is low , blocks that were
previously Locked-Down return to the Lock-Down
state (0,1,x) regardless of any changes made
while WP

was high. Device reset or power-down
resets all blocks , including those in Lock-Down, to
the Locked state.

Locking Operations During Erase Suspend

Changes to block lock status can be performed
during an erase suspend by using the standard
locking command sequences to unlock, lock or
lock-down a block. This is useful in the case when
another block needs to be updated while an erase
operation is in progress.

To change block locking during an erase opera­tion, first write the Erase Suspend command, then
check the status register until it indicates that the
erase operation has been suspended. Next write
the desired Lock com mand sequence to a block
and the lock status will be changed. After complet­ing any desired lock, read, or program operations,
resume the erase operation with the Erase Re­sume command.

If a block is locked or locked-down during an erase
suspend of the same block, the locking status bits
will be changed immediately, b ut when the erase
is resumed, the erase operation will complete.

Locking operations cannot be performed du ring a
program suspend. Refer to Appendix D, Com­mand Interface and Program/Erase Controller
State, for detailed information on which com­mands are valid during erase suspend.

Table 9. Block Lock Status

Item Address Data

Block Lock Configuration

Block is Unlocked DQ0=0

Block is Locked DQ0=1

Block is Locked-Down DQ1=1

LOCK

xx002

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