AT52SC1283J datasheet(7/52 Pages) ATMEL

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3530B–STKD–2/4/05

AT52SC1283J/1284J [Preliminary]

6.9

Reset

A RESET input pin is provided to ease some system applications. When RESET is at a logic

high level, the device is in its standard operating mode. A low level on the RESET pin halts the

present device operation and puts the outputs of the device in a high-impedance state. When a

high level is reasserted on the RESET pin, the device returns to read mode.

6.10

Erase

Before a word can be reprogrammed it must be erased. The erased state of the memory bits is a

logical “1”. The entire memory can be erased by using the Chip Erase command or individual

planes can be erased by using the Plane Erase command or individual sectors can be erased by

using the Sector Erase command.

6.10.1

Chip Erase

Chip Erase is a two-bus cycle operation. The automatic erase begins on the rising edge of the

last WE pulse. Chip Erase does not alter the data of the protected sectors. The hardware reset

during chip erase will stop the erase, but the data will be of an unknown state.

6.10.2

Plane Erase

As an alternative to a full Chip Erase, the device is organized into thirty-two planes (PA0 -

PA31). The Plane Erase command is a two-bus cycle operation which can be used to individu-

ally erase any one of the thirty (PA1 - PA30) planes. The plane whose address is valid at the

second rising edge of WE will be erased. The Plane Erase command does not alter the data in

the protected sectors.

6.10.3

Sector Erase

The device is organized into multiple sectors that can be individually erased. The Sector Erase

command is a two-bus cycle operation. The sector whose address is valid at the second rising

edge of WE will be erased provided the given sector has not been protected.

6.11

Word Programming

The device is programmed on a word-by-word basis. Programming is accomplished via the

internal device command register and is a two-bus cycle operation. The programming address

and data are latched in the second cycle. The device will automatically generate the required

internal programming pulses. Please note that a “0” cannot be programmed back to a “1”; only

erase operations can convert “0”s to “1”s.

6.12

Flexible Sector Protection

The AT52SC1283J/1284J offers two sector protection modes, the Softlock and the Hardlock.

The Softlock mode is optimized as sector protection for sectors whose content changes fre-

quently. The Hardlock protection mode is recommended for sectors whose content changes

infrequently. Once either of these two modes is enabled, the contents of the selected sector is

read-only and cannot be erased or programmed. Each sector can be independently pro-

grammed for either the Softlock or Hardlock sector protection mode. At power-up and reset, all

sectors have their Softlock protection mode enabled.

AT52SC1283J 数据表(PDF) 7 Page - ATMEL Corporation

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