M95P16-EXCSSLASHEF datasheet(40/63 Pages) STMICROELECTRONICS

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6.23

Enable reset (66h) and Software reset (99h)

The Enable reset (RSTEN) and Software reset (RESET) instructions reset the device.

The RSTEN instruction enables the RESET instruction.

The RSTEN instruction is initiated by driving S low and shifting the instruction code 66h into the D pin. The S

pin must be held low for the entire length of the instruction . Pin S must be driven high after the eighth bit has

been latched. Once the S pin is driven high, the RESET instruction is initiated by driving S low and shifting the

instruction code 99h into the D pin. The S pin must be held low for the entire length of the instruction . Pin S must

be driven high after the eighth bit has been latched, otherwise the instruction is not executed.

To avoid accidental resets, these two instructions must be issued in sequence. Any command other than a

Software reset (99h) after an Enable reset (66h) command disables the Reset enable state. A new sequence of

Enable reset (66h) and Software reset (99h) is needed to reset the device. Once the Reset command is accepted

by the device, the reset is effective after a delay given in Table 16. Reset recovery time. During this period, no

command is accepted.

Figure 33. Software reset

High impedance

RESET instruction

RSTEN instruction

MS55473V1

RSTEN and RESET instructions are understood in Deep power-down mode.

When the device is in Deep Power mode or Standby mode, a Software reset command can be decoded and

executed. In this case, the device is reset, and after tRST1 or tRST2 it enters in Standby mode, ready to accept all

instructions.

When the device is executing a modify operation (including Write Status register command) a Software reset

command can be decoded and executed. In this case either: the ongoing operation is properly completed: the

device is reset it goes in Standby mode, ready to accept all instructions or the ongoing operating does not finish

correctly, the data being processed can be damaged or lost, the device resets and it goes in Standby mode, ready

to accept all instructions.

M95P16-I M95P16-E

Enable reset (66h) and Software reset (99h)

DS13710 - Rev 1

page 40/63

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