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M58WR064FB

64 Mbit (4Mb x16, Multiple Bank, Burst) 1.8V Supply Flash Memory

STMicroelectronics 

M58WR064FT, M58WR064FB

SIGNAL DESCRIPTIONS

See Figure 2., Logic Diagram and Table 1., Signal

Names, for a brief overview of the signals connect-

ed to this device.

Address Inputs (A0-A21). The Address Inputs

select the cells in the memory array to access dur-

ing Bus Read operations. During Bus Write opera-

tions they control the commands sent to the

Command Interface of the Program/Erase Con-

troller.

Data Input/Output (DQ0-DQ15). The Data I/O

output the data stored at the selected address dur-

ing a Bus Read operation or input a command or

the data to be programmed during a Bus Write op-

eration.

Chip Enable (E). The Chip Enable input acti-

vates the memory control logic, input buffers, de-

coders and sense amplifiers. When Chip Enable is

at VILand Reset is at VIH the device is in active

mode. When Chip Enable is at VIH the memory is

deselected, the outputs are high impedance and

the power consumption is reduced to the standby

level.

Output Enable (G). The Output Enable input

controls data outputs during the Bus Read opera-

tion of the memory.

Write Enable (W). The Write Enable input con-

trols the Bus Write operation of the memory’s

Command Interface. The data and address inputs

are latched on the rising edge of Chip Enable or

Write Enable whichever occurs first.

Write Protect (WP). Write Protect is an input

that gives an additional hardware protection for

each block. When Write Protect is at VIL, the Lock-

Down is enabled and the protection status of the

Locked-Down blocks cannot be changed. When

Write Protect is at VIH, the Lock-Down is disabled

and the Locked-Down blocks can be locked or un-

locked. (refer to Table 13., Lock Status).

Reset (RP). The Reset input provides a hard-

ware reset of the memory. When Reset is at VIL,

the memory is in reset mode: the outputs are high

impedance and the current consumption is re-

duced to the Reset Supply Current IDD2. Refer to

Table 18., DC Characteristics - Currents, for the

value of IDD2. After Reset all blocks are in the

Locked state and the Configuration Register is re-

set. When Reset is at VIH, the device is in normal

operation. Exiting reset mode the device enters

asynchronous read mode, but a negative transi-

tion of Chip Enable or Latch Enable is required to

ensure valid data outputs.

The Reset pin can be interfaced with 3V logic with-

out any additional circuitry. It can be tied to VRPH

(refer to Table 19., DC Characteristics - Voltages).

Latch Enable (L). Latch Enable latches the ad-

dress bits on its rising edge. The address

latch is transparent when Latch Enable is at

VIL and it is inhibited when Latch Enable is at

VIH. Latch Enable can be kept Low (also at

board level) when the Latch Enable function

is not required or supported.

Clock (K). The clock input synchronizes the

memory to the microcontroller during synchronous

read operations; the address is latched on a Clock

edge (rising or falling, according to the configura-

tion settings) when Latch Enable is at VIL. Clock is

don't care during asynchronous read and in write

operations.

Wait (WAIT). Wait is an output signal used during

synchronous read to indicate whether the data on

the output bus are valid. This output is high imped-

ance when Chip Enable is at VIH or Reset is at VIL.

It can be configured to be active during the wait cy-

cle or one clock cycle in advance. The WAIT signal

is not gated by Output Enable.

VDD Supply Voltage . VDD provides the power

supply to the internal core of the memory device.

It is the main power supply for all operations

(Read, Program and Erase).

VDDQ Supply Voltage. VDDQ provides the power

supply to the I/O pins and enables all Outputs to

be powered independently of VDD. VDDQ can be

tied to VDD or can use a separate supply.

VPP Program Supply Voltage. VPP is a power

supply pin. The Supply Voltage VDD and the Pro-

gram Supply Voltage VPP can be applied in any or-

der. The pin can also be used as a control input.

In the device the two functions are selected by the

voltage range applied to the pin. If VPP is kept in a

low voltage range (0V to VDDQ) VPP is seen as a

control input. In this case a voltage lower than VP-

PLK gives an absolute protection against program

or erase, while VPP > VPP1 enables these func-

tions (see Tables 18 and 19, DC Characteristics

for the relevant values). VPP is only sampled at the

beginning of a program or erase; a change in its

value after the operation has started does not

have any effect and program or erase operations

continue.

If VPP is in the range of VPPH it acts as a power

supply pin. In this condition VPP must be stable un-

til the Program/Erase algorithm is completed.

VSS Ground. VSS ground is the reference for the

core supply. It must be connected to the system

ground.

VSSQ Ground. VSSQ ground is the reference for

the input/output circuitry driven by VDDQ. VSSQ

must be connected to VSS

11/87

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