This Data Sheet may be revised by subsequent versions

©2003 Eon Silicon Solution, Inc., www.essi.com.tw

or modifications due to changes in technical specifications.

6

EN29F040A

Rev. B, Issue Date: 2004/04/01

USER MODE DEFINITIONS

Standby Mode

The EN29F040A has a CMOS-compatible standby mode, which reduces the current to

< 1µA

The device

Read Mode

The device is automatically set to reading array data after device power-up. No commands are

required to retrieve data. The device is also ready to read array data after completing an Embedded

Program or Embedded Erase algorithm.

After the device accepts an Erase Suspend command, the device enters the Erase Suspend mode.

The system can read array data using the standard read timings, except that if it reads at an address

within erase-suspended sectors, the device outputs status data. After completing a programming

operation in the Erase Suspend mode, the system may once again read array data with the same

exception. See “Erase Suspend/Erase Resume Commands” for more information on this mode.

The system must issue the reset command to re-enable the device for reading array data if DQ5

goes high, or while in the autoselect mode. See “Reset Command” section.

See also “Requirements for Reading Array Data” in the “Device Bus Operations” section for more

information. The Read Operations table provides the read parameters, and Read Operation Timings

diagram shows the timing diagram.

Output Disable Mode

output pins are placed in a high impedance state.

Auto Select Identification Mode

The autoselect mode provides manufacturer and device identification, and sector protection

verification, through identifier codes output on DQ7–DQ0. This mode is primarily intended for

programming equipment to automatically match a device to be programmed with its corresponding

programming algorithm. However, the autoselect codes can also be accessed in-system through the

command register.

address pin A9. Address pins A6, A1, and A0 must be as shown in Autoselect Codes (High Voltage

Method) table. In addition, when verifying sector protection, the sector address must appear on the

appropriate highest order address bits. Refer to the corresponding Sector Address Tables. The

Command Definitions table shows the remaining address bits that are don’t care. When all

necessary bits have been set as required, the programming equipment may then read the

corresponding identifier code on DQ7–DQ0.

To access the autoselect codes in-system; the host system can issue the autoselect command via

the command register, as shown in the Command Definitions table. This method does not require