— Guaranteed RESET Assertion to VCC = 1V
— 150ms Reset Pulse Width
— Internal 1.26V Reference with ±1% Accuracy
— ZERO External Components Required
• Watchdog Timer
— Nominal 1.6 Second Time-out Period
— Reset by Any Transition of CS
• Memory
— 1K-bit Microwire Memory
— S93WD462
– Internally Ties ORG Low
– 100% Compatible With all 8-bit
Implementations
–
Sixteen Byte Page Write Capability
— S93WD463
– Internally Ties ORG High
– 100% Compatible With all 16-bit
Implementations
– Eight Word Page Write Capability
OVERVIEW
The S93WD462 and S93WD463 are precision power
supervisory circuits providing both active high and
active low reset output. Both devices also incorporate a
watchdog timer with a nominal time-out value of 1.6
seconds.
Both devices have 1k-bits of E
2
PROM memory that is
accessible via the industry standard microwire bus. The
S93WD462 is configured with an internal ORG pin tied
low providing a 8-bit byte organization and the
S93WD463 is configured with an internal ORG pin tied
high providing a 16-bit word organization. Both the
S93WD462 and S93WD463 have page write capabil-
ity. The devices are designed for a minimum 100,000
program/erase cycles and have data retention in ex-
CSChip Select
SKClock Input
DISerial Data Input
DOSerial Data Output
V
CC
+2.7 to 6.0V Power Supply
GNDGround
RESET/RESET#RESET I/O
DEVICE OPERATION
APPLICATIONS
The S93WD462/WD463 is ideal for applications requiring low voltage and low power consumption. This device
provides microcontroller RESET control and can be
manually resettable.
S93WD462/S93WD463
. The reset outputs will be valid so long as VCC is ≥
V
TRIP
1.0V. During power-down, the reset outputs will begin
driving active when VCC falls below V
The reset pins are I/Os; therefore, the S93WD462/
WD463 can act as a signal conditioning circuit for an
externally applied reset. The inputs are edge triggered;
that is, the RESET input will initiate a reset time-out after
detecting a low to high transition and the RESET# input
will initiate a reset time-out after detecting a high to low
transition. Refer to the applications Information section
for more details on device operation as a debounce/
reset extender circuit.
It should be noted the reset outputs are open drain. When
used as outputs driving a circuit they need to be either
tied high (RESET#) or tied to ground (RESET) through
the use of pull-up or pull-down resistors. Refer to the
applications aid section for help in determining the value
of resistor to be used. Internally these pins are weakly
pulled up (RESET#) and pulled down (RESET): therefore, if the signals are not being used the pins may be left
unconnected.
WATCHDOG TIMER DESCRIPTION
The S93WD462/WD463 has a watchdog timer with a
nominal time-out period of 1.6 seconds. Whenever the
watchdog times out, it will generate a reset output to both
pins 6 and 7. The watchdog timer is reset by any
transition on CS.
The watchdog timer will be held in a reset state during
power-on while V
exceeds V
TRIP
a reset state for the t
is less than V
CC
the watchdog will continue to be held in
period. After t
PURST
released and the timer will begin operation. If either reset
input is asserted the watchdog timer will be reset and
remain in the reset condition until either t
expired or the reset input is released, whichever is
longer.
TRIP
TRIP
PURST
.
. Once V
it will be
PURST
CC
has
RESET CONTROLLER DESCRIPTION
The S93WD462/WD463 provides a precision reset controller that ensures correct system operation during
brownout and power-up/-down conditions. It is configured with two open drain reset outputs; pin 7 is an active
high output and pin 6 is an active low output.
During power-up, the reset outputs remain active until
VCC reaches the V
threshold. The outputs will con-
TRIP
tinue to be driven for approximately 150ms after reaching
2
2029 2.2 1/23/01
GENERAL OPERATION
The S93WD462/WD463 is a 1024-bit nonvolatile memory
intended for use with industry standard microprocessors. The S93WD463 is organized as X16, seven 9-bit
instructions control the reading, writing and erase
operations of the device. The S93WD462 is organized
as X8, seven 10-bit instructions control the reading,
writing and erase operations of the device. The device
operates on a single 3V or 5V supply and will generate on
chip, the high voltage required during any write operation.
SUMMIT MICROELECTRONICS, Inc.
Page 3
S93WD462/S93WD463
Instructions, addresses, and write data are clocked into
the DI pin on the rising edge of the clock (SK). The DO
pin is normally in a high impedance state except when
reading data from the device, or when checking the
ready/busy status after a write operation.
The ready/busy status can be determined after the start
of a write operation by selecting the device (CS high)
and polling the DO pin; DO low indicates that the write
operation is not completed, while DO high indicates that
the device is ready for the next instruction. See the
Applications Aid section for detailed use of the ready
busy status.
The format for all instructions is: one start bit; two op
code bits and either six (x16) or seven (x8) address or
instruction bits.
t
SKHI
SK
t
DIS
DI
VALIDVALID
Read
Upon receiving a READ command and an address
(clocked into the DI pin), the DO pin of the S93WD462/
WD463 will come out of the high impedance state and,
will first output an initial dummy zero bit, then begin
shifting out the data addressed (MSB first). The output
data bits will toggle on the rising edge of the SK clock and
are stable after the specified time delay
(t
PD0
or t
PD1
).
Write
After receiving a WRITE command, address and the
data, the CS (Chip Select) pin must be deselected for a
minimum of 250ns (t
). The falling edge of CS will
CSMIN
start automatic erase and write cycle to the memory
location specified in the instruction. The ready/busy
status of the S93WD462/WD463 can be determined by
selecting the device and polling the DO pin.
t
SKLOW
t
DIH
t
CSH
CS
DO
CS
DO
SK
DI
t
CSS
11 0
t
DIS
Figure 1. Sychronous Data Timing
ANA
N–1
t
PD0
A
0
0
DND
Figure 2. Read Instruction Timing
N–1
t
PD0,tPD1
DATA VALID
D1D
t
CSMIN
2029 ILL 3.0
t
CS
STANDBY
t
HZ
0
HIGH-ZHIGH-Z
2029 ILL4.0
2029 2.2 1/23/01SUMMIT MICROELECTRONICS, Inc.
3
Page 4
S93WD462/S93WD463
Erase
Upon receiving an ERASE command and address, the
CS (Chip Select) pin must be deselected for a minimum
of 250ns (t
). The falling edge of CS will start the
CSMIN
auto erase cycle of the selected memory location. The
ready/busy status of the S93WD462/WD463 can be
determined by selecting the device and polling the DO
pin. Once cleared, the content of a cleared location
returns to a logical “1” state.
Erase/Write Enable and Disable
The S93WD462/WD463 powers up in the write disable
state. Any writing after power-up or after an EWDS
(write disable) instruction must first be preceded by the
EWEN (write enable) instruction. Once the write instruction is enabled, it will remain enabled until power to
the device is removed, or the EWDS instruction is sent.
The EWDS instruction can be used to disable all
S93WD462/WD463 write and clear instructions, and
will prevent any accidental writing or clearing of the
device. Data can be read normally from the device
regardless of the write enable/disable status.
Erase All
Upon receiving an ERAL command, the CS (Chip Select) pin must be deselected for a minimum of 250ns
(t
). The falling edge of CS will start the self clocking
CSMIN
clear cycle of all memory locations in the device. The
clocking of the SK pin is not necessary after the device
has entered the self clocking mode. The ready/busy
status of the S93WD462/WD463 can be determined by
selecting the device and polling the DO pin. Once
cleared, the contents of all memory bits will be in a
logical “1” state.
Write All
Upon receiving a WRAL command and data, the CS
(Chip Select) pin must be deselected for a minimum of
250ns (t
). The falling edge of CS will start the self
CSMIN
clocking data write to all memory locations in the device.
The clocking of the SK pin is not necessary after the
device has entered the self clocking mode. The ready/
busy status of the S93WD462/WD463 can be determined by selecting the device and polling the DO pin. It
is not necessary for all memory locations to be cleared
before the WRAL command is executed.
Page Write
93WD462 - Assume WEN has been issued. The host
will then take CS high, and begin clocking in the start
bit, write command and 7-bit address immediately
followed by the first byte of data to be written. The host
can then continue clocking in 8-bit bytes of data with
each byte to be written to the next higher address.
Internally the address pointer is incremented after
receiving each group of eight clocks; however, once
the address counter reaches xxx 1111 it will roll over
to xxx 0000 with the next clock. After the last bit is
clocked in no internal write operation will occur until CS
is brought low.
93WD463 - Assume WEN has been issued. The host
will then take CS high, and begin clocking in the start
bit, write command and 6-bit address immediately
followed by the first 16-bit word of data to be written.
The host can then continue clocking in 16-bit words of
data with each word to be written to the next higher
address. Internally the address pointer is incremented
after receiving each group of sixteen clocks; however,
once the address counter reaches xxx x111 it will roll
over to xx x000 with the next clock. After the last bit is
clocked in no internal write operation will occur until CS
is brought low.
Continuous Read
This begins just like a standard read with the host
issuing a read instruction and clocking out the data
byte [word]. If the host then keeps CS high and
continues generating clocks on SK, the S93WD462/
WD463 will output data from the next higher address
location. The S93WD462/WD463 will continue
incrementing the address and outputting data so long
as CS stays high. If the highest address is reached, the
address counter will roll over to address 0000. CS
going low will reset the instruction register and any
subsequent read must be initiated in the normal manner of issuing the command and address.
WRAL10001xxxxx01xxxx D7–D0 D15–D0Write All Addresses
2029 PGM T5.0
6
2029 2.2 1/23/01
SUMMIT MICROELECTRONICS, Inc.
Page 7
S93WD462/S93WD463
ABSOLUTE MAXIMUM RATINGS*
Temperature Under Bias ....................................................................................................................................–55°C to +125°C
Storage Temperature .........................................................................................................................................–65°C to +150°C
Voltage on any Pin with Respect to Ground
VCC with Respect to Ground..................................................................................................................................–2.0V to +7.0V
Package Power Dissipation Capability (Ta = 25°C) .............................................................................................................1.0W
Lead Soldering Temperature (10 secs) .............................................................................................................................. 300°C
Output Short Circuit Current
*COMMENT
Stresses above those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions outside of those listed in the operational sections of this specification is not implied. Exposure to
any absolute maximum rating for extended periods may affect device performance and reliability.
(2)
...........................................................................................................................................100 mA
RECOMMENDED OPERATING CONDITIONS
TemperatureMinMax
Commercial0°C+70°C
Industrial-40°C+85°C
RELIABILITY CHARACTERISTICS
SymbolParameterMin.Max.UnitsReference Test Method
(3)
N
T
V
I
LTH
END
DR
ZAP
(3)
(3)
(3)(4)
Endurance100,000Cycles/ByteMIL-STD-883, Test Method 1033
Data Retention100YearsMIL-STD-883, Test Method 1008
ESD Susceptibility2000VoltsMIL-STD-883, Test Method 3015
Latch-Up100mAJEDEC Standard 17
.............................................................................................–2.0V to +VCC +2.0V
2029 PGM T7.0
2029 PGM T2.1
Limits
Output Open
I
SB
Power Supply Current50µACS = 0V
(Standby)Reset Outputs Open
I
LI
I
LO
Input Leakage Current2µAVIN = 0V to V
Output Leakage Current10µAV
= 0V to VCC,
OUT
CC
(Including ORG pin)CS = 0V
V
V
V
V
V
V
IL1
IH1
IL2
IH2
OL1
OH1
Input Low Voltage-0.10.8V4.5V-VCC<5.5V
Input High Voltage2VCC+1V
Input Low Voltage0VCCX0.2V1.8V-VCC<2.7V
Input High VoltageVCCX0.7VCC+1V
Output Low Voltage0.4V4.5V-VCC<5.5V
Output High Voltage2.4VIOL = 2.1mA
IOH = -400µA
V
V
OL2
OH2
Output Low Voltage0.2V1.8V-VCC<2.7V
Output High VoltageVCC-0.2VIOL = 1mA
IOH = -100µA
Note:
(1) The minimum DC input voltage is –0.5V. During transitions, inputs may undershoot to –2.0V for periods of less than 20 ns. Maximum DC
voltage on output pins is VCC +0.5V, which may overshoot to VCC +2.0V for periods of less than 20 ns.
(2) Output shorted for no more than one second. No more than one output shorted at a time.
(3) This parameter is tested initially and after a design or process change that affects the parameter.
(4) Latch-up protection is provided for stresses up to 100 mA on address and data pins from –1V to VCC +1V.
2029 2.2 1/23/01SUMMIT MICROELECTRONICS, Inc.
2029 PGM T3.0
7
Page 8
S93WD462/S93WD463
PIN CAPACITANCE
SymbolTestMax.UnitsConditions
(1)
C
OUT
C
IN
Note:
(1) This parameter is tested initially and after a design or process change that affects the parameter.
A.C. CHARACTERISTICS (over recommended operating conditions unless otherwise specified)
SYMBOL PARAMETERMin.Max.Min.Max. UNITS Conditions
OUTPUT CAPACITANCE (DO)5pFV
(1)
INPUT CAPACITANCE (CS, SK, DI, ORG)5pFVIN=OV
Limits
VCC=2.7V-4.5V VCC=4.5V-5.5V Test
OUT
=OV
2029 PGM T4.0
t
CSS
t
CSH
t
DIS
t
DIH
t
PD1
t
PD0
(1)
t
HZ
t
EW
t
CSMIN
t
SKHI
t
SKLOW
t
SV
SK
MAX
Note:
(1) This parameter is tested initially and after a design or process change that affects the parameter.
CS Setup Time10050ns
CS Hold Time00nsVIL = 0.45V
DI Setup Time200100nsVIH = 2.4V
DI Hold Time200100nsCL = 100pF
Output Delay to 10.50.25µsVOL = 0.8V
Output Delay to 00.50.25µsVOH = 2.0v
Output Delay to High-Z200100ns
Program/Erase Pulse Width1010ms
Minimum CS Low Time0.50.25µs
Minimum SK High Time0.50.25µs
Minimum SK Low Time0.50.25µs
Output Delay to Status Valid0.50.25µsCL = 100pF
Maximum Clock FrequencyDC500DC1000KHZ
CL = 100pF
2029 PGM T6.0
8
2029 2.2 1/23/01
SUMMIT MICROELECTRONICS, Inc.
Page 9
S93WD462/S93WD463
RESET CIRCUIT AC and DC ELECTRICAL CHARACTERISTICS
2.75 Volt-A5 Volt-B
SymbolParameterMinMaxMinMaxMinMaxUnit
V
TRIP
t
PURST
t
RPD
V
RVALID
t
GLITCH
V
OLRS
V
OHRS
Reset Trip Point2.552.74.254.54.504.75V
Power-Up Reset Timeout130270130270130270ms
V
RESET# Output Low Voltage IOL=1mA0.40.40.4V
RESET Output High I
V
TRIP
OH
VCC-.75VCC-.75 VCC-.75V
t
GLITCH
2029 PGM T1.0
V
CC
RESET#
RESET
V
RVALID
t
RPD
t
PURST
Figure 8. RESET Timing Diagram
t
PURST
t
RPD
2029 T fig08 2.0
2029 2.2 1/23/01SUMMIT MICROELECTRONICS, Inc.
9
Page 10
0.053 - 0.069
(1.35 - 1.75)
1
0.189 - 0.196
(4.80 - 5.00)
0.150 - 0.157
(3.80 - 4.00)
8 Pin SOIC
S93WD462/S93WD463
Ref. JEDEC MS-012
Inches
(Millimeters)
0.010 - 0.020
(0.25 - 0.50)
×45º
0.013 - 0.020
(0.33 - 0.51)
Ref. JEDEC MS-001
(Millimeters)
0.300 - 0.325
(7.62 - 8.25)
Inches
0.004 - 0.010
(0.10 - 0.25)
.05 (1.27) TYP.
8 Pin PDIP
PIN 1 INDICATOR
0.045 - 0.070
(1.14 - 1.78)
0.21
(5.33)
0.016 - 0.050
(0.40 - 1.27)
0.355 - 0.400
(9.02 - 10.2)
MAX.
0.228 - 0.244
(5.80 - 6.20)
0.24 - 0.28
(6.1 - 7.1)
0.115 - 0.195
(2.92 - 4.95)
.015
(.381)
8 Pin SOIC
Min.
10
0.43
(10.9)
MAX.
0.008 - 0.014
(0.20 - 0.36)
SEATING PLANE
0.014 - 0.022
2029 2.2 1/23/01
(0.36 - 0.56)
1
.100
(2.54)
0.115 - 0.195
(2.92 - 4.95)
8 Pin PDIP
SUMMIT MICROELECTRONICS, Inc.
Page 11
S93WD462/S93WD463
Frequently the reset controller will be deployed on a PC board that provides a peripheral function to a system.
Examples might be modem or network cards in a PC or a PCMCIA card in a laptop. In instances like this the peripheral
card may have a requirement for a clean reset function to insure proper operation. The system may or may not provide
a reset pulse of sufficient duration to clear the peripheral or to protect data stored in a nonvolatile memory.
The I/O capability of the RESET pins can provide a solution. The system’s reset signal to the peripheral can be fed
into the S93WD462/WD463 and it in turn can clean up the signal and provide a known entity to the peripheral’s circuits.
The figure below shows the basic timing characteristics under the assumption the reset input is shorter in duration
than t
. The same reset output affect can be attained by using the active high reset input.
PURST
RESET#
Input
RESET#
Output
RESET
Output
t
PURST
2029 T fig09 2.0
When planning your resistor pull-up and pull-down values, use the following chart to help determine min. resistances.
Worst Case RESET Sink/Source Capabilities at Various VCC Levels
Ready/Busy Status
During the internal write operation the S93WD462/WD463 memory array is inaccessible. After starting the write
operation (taking CS low) the host can implement a 10ms timeout routine or alternatively it can employ a polling routine
that tests the state of the DO pin.
After starting the write, testing for the status is easily accomplished by taking CS high and testing the state of DO. If
it is low the device is still busy with the internal write. If it is high the write operation has completed.
For the polling routine the host has the option of toggling CS for each test of DO, or it can place CS high and then
intermittently test DO. SK is not required for any of these operations. Once the device is ready, it will continue to drive
DO high whenever the S93WD462/WD463 is selected. The ready state of DO can be cleared by clocking in a start
bit; this start bit can either be the beginning of a new command sequence or it can be a dummy start bit with CS returning
low before the host issues a new command.
SUMMIT Microelectronics, Inc. reserves the right to make changes to the products contained in this publication in
order to improve design, performance or reliability. SUMMIT Microelectronics, Inc. assumes no responsibility for
the use of any circuits described herein, conveys no license under any patent or other right, and makes no
representation that the circuits are free of patent infringement. Charts and schedules contained herein reflect
representative operating parameters, and may vary depending upon a user’s specific application. While the
information in this publication has been carefully checked, SUMMIT Microelectronics, Inc. shall not be liable for any
damages arising as a result of any error or omission.
SUMMIT Microelectronics, Inc. does not recommend the use of any of its products in life support or aviation
applications where the failure or malfunction of the product can reasonably be expected to cause any failure of either
system or to significantly affect their safety or effectiveness. Products are not authorized for use in such applications
unless SUMMIT Microelectronics, Inc. receives written assurances, to its satisfaction, that: (a) the risk of injury or
damage has been minimized; (b) the user assumes all such risks; and (c) potential liability of SUMMIT
Microelectronics, Inc. is adequately protected under the circumstances.