MBM29F040C datasheet(11/41 Pages) SPANSION

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MBM29F040C-55/-70/-90

* : Outputs 01H at protected sector addresses and 00H at unprotected sector addresses.

Write

Device erasure and programming are accomplished via the command register. The contents of the register serve

as inputs to the internal state machine. The state machine outputs dictate the function of the device.

The command register itself does not occupy any addressable memory location. The register is a latch used to

store the commands, along with the address and data information needed to execute the command. The

command register is written by bringing WE to VIL, while CE is at VIL and OE is at VIH. Addresses are latched on

the falling edge of WE or CE, whichever happens later; while data is latched on the rising edge of WE or CE,

whichever happens first. Standard microprocessor write timings are used.

Refer to AC Write Characteristics and the Erase/Programming Waveforms for specific timing parameters.

Sector Protection

The MBM29F040C features hardware sector protection. This feature will disable both program and erase

operations in any number of sectors (0 through 8). The sector protection feature is enabled using programming

equipment at the user’s site. The device is shipped with all sectors unprotected.

To activate this mode, the programming equipment must force VID on address pin A9 and control pin OE, (suggest

VID = 11.5 V) and CE = VIH. The sector addresses (A18, A17 and A16) should be set to the sector to be protected.

Table 4 defines the sector address for each of the eight (8) individual sectors. Programming of the protection

circuitry begins on the falling edge of the WE pulse and is terminated with the rising edge of the same. Sector

addresses must be held constant during the WE pulse. See figures 11 and 17 sector protection waveforms and

algorithm.

Table 3

MBM29F040C Sector Protection Verify Autoselect Codes

Type

A18

A17

A16

Code

(HEX) DQ

DQ6 DQ5 DQ4 DQ3 DQ2 DQ1 DQ0

Manufacture’s

Code

XXX

VIL

04H

00000100

Device Code

VIL

VIH

A4H

10100100

Sector

Protection

Sector

Addresses

VIL

VIH

VIL

01H*

00000001

Table 4

Sector Address Tables

Sector Address

A18

A17

A16

Address Range

SA0

00000H to 0FFFFH

SA1

10000H to 1FFFFH

SA2

20000H to 2FFFFH

SA3

30000H to 3FFFFH

SA4

40000H to 4FFFFH

SA5

50000H to 5FFFFH

SA6

60000H to 6FFFFH

SA7

70000H to 7FFFFH

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