This Data Sheet may be revised by subsequent versions

©2004 Eon Silicon Solution, Inc., www.essi.com.tw

or modifications due to changes in technical specifications.

7

EN25F40

Rev. B, Issue Date: 2007/05/09

TABLE 3. Protected Area Sizes Sector Organization

Status Register

Content

Memory Content

BP2

Bit

BP1

Bit

BP0

Bit

Protect Blocks

Addresses

Density(KB)

Portion

1

1

1

All

000000h-0FFFFFh

512KB

All

1

1

0

All

000000h-0FFFFFh

512KB

All

1

0

1

All

000000h-0FFFFFh

512KB

All

1

0

0

All

000000h-0FFFFFh

512KB

All

0

1

1

4 to 7

040000h-07FFFFh

256KB

Upper 1/2

0

1

0

6 to 7

060000h-07FFFFh

128KB

Upper 1/4

0

0

1

7

070000h-07FFFFh

64KB

Upper 1/8

0

0

0

None

None

None

None

Hold Function

The Hold (HOLD) signal is used to pause any serial communications with the device without resetting the

clocking sequence. However, taking this signal Low does not terminate any Write Status Register,

Program or Erase cycle that is currently in progress.

To enter the Hold condition, the device must be selected, with Chip Select (CS#) Low. The Hold condition

starts on the falling edge of the Hold (HOLD) signal, provided that this coincides with Serial Clock (CLK)

being Low (as shown in Figure 4.).

The Hold condition ends on the rising edge of the Hold (HOLD) signal, provided that this coincides with

Serial Clock (CLK) being Low.

If the falling edge does not coincide with Serial Clock (CLK) being Low, the Hold condition starts after

Serial Clock (CLK) next goes Low. Similarly, if the rising edge does not coincide with Serial Clock (CLK)

being Low, the Hold condition ends after Serial Clock (CLK) next goes Low. (This is shown in Figure 4.).

During the Hold condition, the Serial Data Output (DO) is high impedance, and Serial Data Input (DI) and

Serial Clock (CLK) are Don’t Care.

Normally, the device is kept selected, with Chip Select (CS#) driven Low, for the whole duration of the

Hold condition. This is to ensure that the state of the internal logic remains unchanged from the moment

of entering the Hold condition.

If Chip Select (CS#) goes High while the device is in the Hold condition, this has the effect of resetting the

internal logic of the device. To restart communication with the device, it is necessary to drive Hold (HOLD)

High, and then to drive Chip Select (CS#) Low. This prevents the device from going back to the Hold

condition.

Figure 4. Hold Condition Waveform