The data is then clocked out serially. The address

pointer is automatically incremented after the data

is output and, if the Chip Select input (S) is held

High, the ST93CS56/57 can output a sequential

stream of data words. In this way, the memory can

be read as a data stream of 16 to 2048 bits, or

continuously as the address counter automatically

rolls over to 00 when the highest address is

reached. Within the time required by a program-

the help of the Page Write instruction; the whole

memory may also be erased, or set to a predeter-

mined pattern, by using the Write All instruction.

Within the memory, an user defined area may be

protected against further Write instructions. The

size of this area is defined by the content of a

Protect Register, located outside of the memory

array. As a final protection step, data may be per-

manently protected by programming a One Time

Programing bit (OTP bit) which locks the Protect

Register content.

Programming is internally self-timed (the external

clock signal on C input may be disconnected or left

running after the start of a Write cycle) and does

not require an erase cycle prior to the Write instruc-

tion. The Write instruction writes 16 bits at one time

into one of the 128 words, the Page Write instruc-

tion writes up to 4 words of 16 bits to sequential

locations, assuming in both cases that all ad-

dresses are outside the Write Protected area.

After the start of the programming cycle, a

Ready/Busy signal is available on the Data output

(Q) when the Chip Select (S) input pin is driven

High.

VSS

Q

W

PRE

C

SVCC

D

AI00897B

ST93CS56

ST93CS57

1

2

3

4

8

7

6

5

Figure 2A. DIP Pin Connections

1

VSS

Q

W

PRE

C

SVCC

D

AI00898C

ST93CS56

ST93CS57

2

3

4

8

7

6

5

Figure 2B. SO Pin Connections

DESCRIPTION (cont’d)

Symbol

Parameter

Value

Unit

Ambient Operating Temperature

–40 to 85

°C

Storage Temperature

–65 to 150

°C

Lead Temperature, Soldering

(SO8 package)

(PSDIP8 package)

40 sec

10 sec

215

260

°C

V

Supply Voltage

–0.3 to 6.5

V

Electrostatic Discharge Voltage (Human Body model)

(2)

3000

V

Electrostatic Discharge Voltage (Machine model)

(3)

500

V

Notes: 1. Except for the rating ”Operating Temperature Range”, stresses above those listed in the Table ”Absolute Maximum Ratings”

may cause permanent damage to the device. These are stress ratings only and operation of the device at these or any other

conditions above those indicated in the Operating sections of this specification is not implied. Exposure to Absolute Maximum

Rating conditions for extended periods may affect device reliability. Refer also to the SGS-THOMSON SURE Program and other

relevant quality documents.

2. MIL-STD-883C, 3015.7 (100pF, 1500

Ω).

3. EIAJ IC-121 (Condition C) (200pF, 0

Ω).

2/16

ST93CS56, ST93CS57