ST93C56, 56C
ST93C57C
2K (128 x 16 or 256 x 8) SERIAL MICROWIRE EEPROM
NOT FOR NEW DESIGN
1 MILLION ERASE/WRITE CYCLES, with
40 YEARS DATA RETENTION
DUAL ORGANIZATION: 128 x 16 or 256 x 8
BYTE/WORD and ENTIRE MEMORY
PROGRAMMING INSTRUCTIONS
SELF-TIMED PROGRAMMING CYCLE with
AUTO-ERASE
READY/BUSY SIGNAL DURING
PROGRAMMING
SINGLE SUPPLY VOLTAGE:
– 4.5V to 5.5V for ST93C56 version
– 3V to 5.5V for ST93C57 version
SEQUENTIAL READ OPERATION
5ms TYPICAL PROGRAMMING TIME
ST93C56, ST93C56C, ST93C57C are
replaced by the M93C56
DESCRIPTION
This specification covers a range of 2K bit serial
EEPROM products, the ST93C56, 56C specified
at 5V
±
10% and the ST93C57C specified at 3V to
5.5V. In the text, products are referred to as
ST93C56.
The ST93C56 is a 2K bit Electrically Erasable
Programmable Memory (EEPROM) fabricated with
SGS-THOMSON’s High EnduranceSingle Polysili-
con CMOS technology. The memory is accessed
through a serial input (D) and output (Q). The 2K
bit memory is divided into either 256 x 8 bit bytes
or 128 x 16 bit words. The organization may be
selected by a signal applied on the ORG input.
Table 1. Signal Names
S
D
Q
C
ORG
V
CC
V
SS
Chip Select Input
Serial Data Input
Serial Data Output
Serial Clock
Organisation Select
Supply Voltage
Ground
8
1
PSDIP8 (B)
0.4mm Frame
8
1
SO8 (M)
150mil Width
Figure 1. Logic Diagram
VCC
D
C
S
ORG
ST93C56
ST93C57
Q
VSS
AI00881C
June 1997
This is information on a product still in production bu t not recommended for new de signs.
1/13
ST93C56/56C, ST93C57C
Figure 2A. DIP Pin Connections
Figure 2B. SO Pin Connections
ST93C56
ST93C57
S
C
D
Q
1
2
3
4
8
7
6
5
AI00882C
ST93C56
ST93C57
VCC
DU
ORG
VSS
S
C
D
Q
1
2
3
4
8
7
6
5
AI00883D
VCC
DU
ORG
VSS
Warning:
DU = Don’t Use
Warning:
DU = Don’t Use
Table 2. Absolute Maximum Ratings
(1)
Symbol
T
A
T
STG
T
LEAD
V
IO
V
CC
V
ESD
Parameter
Ambient Operating Temperature
Storage Temperature
Lead Temperature, Soldering
(SO8 package)
(PSDIP8 package)
40 sec
10 sec
Value
–40 to 125
–65 to 150
215
260
–0.3 to V
CC
+0.5
–0.3 to 6.5
(2)
Unit
°C
°C
°C
V
V
V
V
Input or Output Voltages (Q = V
OH
or Hi-Z)
Supply Voltage
Electrostatic Discharge Voltage (Human Body model)
Electrostatic Discharge Voltage (Machine model)
(3)
4000
500
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).
DESCRIPTION
(cont’d)
The memory is accessed by a set of instructions
which includes Read a byte/word, Write a
byte/word, Erase a byte/word, Erase All and Write
All. A Read instruction loads the address of the first
byte/word to be read into an internal address
pointer. The data contained at this address is then
clocked out serially. The address pointer is auto-
matically incremented after the data is output and,
if the Chip Select input (S) is held High, the
ST93C56 can output a sequential stream of data
bytes/words. In this way, the memory can be read
as a data stream from 8 to 2048 bits long, or
continuously as the address counter automatically
rolls over to ’00’ when the highest address is
reached. Programming is internally self-timed (the
external clock signal on C input may be discon-
2/13
nected or left running after the start of a Write cycle)
and does not require an erase cycle prior to the
Write instruction. The Write instruction writes 8 or
16 bits at one time into one of the 256 bytes or 128
words. After the start of the programming cycle, a
Busy/Ready signal is available on the Data output
(Q) when Chip Select (S) is driven High.
The design of the ST93C56 and the High Endur-
ance CMOS technologyused for its fabrication give
an Erase/Write cycle Endurance of 1,000,000 cy-
cles and a data retention of 40 years.
The DU (Don’t Use) pin does not affect the function
of the memory and it is reserved for use by SGS-
THOMSON during test sequences.The pin may be
left unconnected or may be connected to V
CC
or
V
SS
. Direct connection of DU to V
SS
is recom-
mended for the lowest standby power consump-
tion.
ST93C56/56C, ST93C57C
AC MEASUREMENT CONDITIONS
Input Rise and Fall Times
Input Pulse Voltages
Input Timing Reference Voltages
Output Timing Reference Voltages
≤
20ns
0.4V to 2.4V
1V to 2.0V
0.8V to 2.0V
Figure 3. AC Testing Input Output Waveforms
2.4V
2V
1V
2.0V
0.8V
OUTPUT
AI00815
0.4V
Note that Output Hi-Z is defined as the point where data
is no longer driven.
INPUT
Table 3. Capacitance
(1)
(T
A
= 25
°C,
f = 1 MHz )
Symbol
C
IN
C
OUT
Parameter
Input Capacitance
Output Capacitance
Test Condition
V
IN
= 0V
V
OUT
= 0V
Min
Max
5
5
Unit
pF
pF
Note:
1. Sampled only, not 100% tested.
Table 4. DC Characteristics
(T
A
= 0 to 70°C or –40 to 85°C; V
CC
= 4.5V to 5.5V or 3V to 5.5V)
Symbol
I
LI
I
LO
I
CC
Parameter
Input Leakage Current
Output Leakage Current
Supply Current (TTL Inputs)
Supply Current (CMOS Inputs)
I
CC1
V
IL
Supply Current (Standby)
Input Low Voltage (D, C, S)
Test Condition
0V
≤
V
IN
≤
V
CC
0V
≤
V
OUT
≤
V
CC
,
Q in Hi-Z
S = V
IH
, f = 1 MHz
S = V
IH
, f = 1 MHz
S = V
SS
, C = V
SS
,
ORG = V
SS
or V
CC
V
CC
= 5V
±
10%
3V
≤
V
CC
≤
4.5V
V
CC
= 5V
±
10%
3V
≤
V
CC
≤
4.5V
Output Low Voltage
I
OL
= 2.1mA
I
OL
= 10
µA
I
OH
= –400µA
I
OH
= –10µA
2.4
V
CC
– 0.2
–0.3
–0.3
2
0.8 V
CC
Min
Max
±2.5
±2.5
3
2
50
0.8
0.2 V
CC
V
CC
+ 1
V
CC
+ 1
0.4
0.2
Unit
µA
µA
mA
mA
µA
V
V
V
V
V
V
V
V
V
IH
Input High Voltage (D, C, S)
V
OL
V
OH
Output High Voltage
3/13
ST93C56/56C, ST93C57C
Table 5. AC Characteristics
(T
A
= 0 to 70°C or –40 to 85°C; V
CC
= 4.5V to 5.5V or 3V to 5.5V)
Symbol
t
SHCH
t
CLSH
t
DVCH
t
CHDX
Alt
t
CSS
t
SKS
t
DIS
t
DIH
Parameter
Chip Select High to Clock High
Clock Low to Chip Select High
Input Valid to Clock High
Temp. Range: grade 1
Clock High to Input Transition
Temp. Range:
grades 3, 6
Test Condition
Min
50
100
100
100
200
500
500
0
250
Note 1
250
500
ST93C56
ST93C56C, 57C
t
CHCL
t
CLCH
t
W
f
C
t
SKH
t
SKL
t
WP
f
SK
Clock High to Clock Low
Clock Low to Clock High
Erase/Write Cycle time
Clock Frequency
0
Note 2
Note 2
250
250
10
1
300
200
Max
Unit
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ms
MHz
t
CHQL
t
CHQV
t
CLSL
t
SLCH
t
SLSH
t
SHQV
t
SLQZ
t
PD0
t
PD1
t
CSH
Clock High to Output Low
Clock High to Output Valid
Clock Low to Chip Select Low
Chip Select Low to Clock High
t
CS
t
SV
t
DF
Chip Select Low to Chip Select High
Chip Select High to Output Valid
Chip Select Low to Output Hi-Z
Notes:
1. Chip Select must be brought low for a minimum of 250 ns (t
SLSH
) between consecutive instruction cycles.
2. The Clock frequency specification calls for a minimum clock period of 1
µs,
therefore the sum of the timings t
CHCL
+ t
CLCH
must be greater or equal to 1
µs.
For example, if t
CHCL
is 250 ns, then t
CLCH
must be at least 750 ns.
Figure 4. Synchronous Timing, Start and Op-Code Input
tCLSH
C
tSHCH
S
tDVCH
D
START
OP CODE
tCHCL
tCLCH
tCHDX
OP CODE
START
OP CODE INPUT
AI01428
4/13
ST93C56/56C, ST93C57C
Figure 5. Synchronous Timing, Read or Write
C
tCLSL
S
tDVCH
D
An
tCHQL
Q15/Q7
tCHDX
A0
tSLQZ
Q0
tCHQV
tSLSH
Hi-Z
Q
ADDRESS INPUT
DATA OUTPUT
AI00820C
tSLCH
C
tCLSL
S
tDVCH
D
An
tCHDX
A0/D0
tSHQV
Hi-Z
Q
BUSY
tW
ADDRESS/DATA INPUT
WRITE CYCLE
AI01429
tSLSH
tSLQZ
READY
MEMORY ORGANIZATION
The ST93C56 is organized as 256 bytes x 8 bits or
128 words x 16 bits. If the ORG input is left uncon-
nected (or connected to V
CC
) the x16 organization
is selected, when ORG is connected to Ground
(V
SS
) the x8 organization is selected. When the
ST93C56 is in standby mode, the ORG input
should be unconnected or set to either V
SS
or V
CC
in order to achieve the minimum power consump-
tion. Any voltage between V
SS
and V
CC
applied to
ORG may increase the standby current value.
POWER-ON DATA PROTECTION
In order to prevent data corruption and inadvertent
write operations during power up, a Power On
Reset (POR) circuit resets all internal programming
circuitry and sets the device in the Write Disable
mode. When V
CC
reaches its functional value, the
device is properly reset (in the Write Disable mode)
and is ready to decode and execute an incoming
instruction. A stable V
CC
must be applied, before
applying any logic signal.
5/13