|
|
PDF X4045 Data sheet ( Hoja de datos )
| Número de pieza | X4045 | |
| Descripción | (X4043 / X4045) CPU Supervisor | |
| Fabricantes | Intersil Corporation | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de X4045 (archivo pdf) en la parte inferior de esta página. Total 24 Páginas | ||
|
No Preview Available !
®
Data Sheet
September 30, 2005
X4043, X4045
4k, 512 x 8 Bit
FN8118.1
CPU Supervisor with 4kbit EEPROM
FEATURES
• Selectable watchdog timer
• Low VCC detection and reset assertion
—Five standard reset threshold voltages
—Adjust low VCC reset threshold voltage using
special programming sequence
—Reset signal valid to VCC = 1V
• Low power CMOS
—<20µA max standby current, watchdog on
—<1µA standby current, watchdog OFF
—3mA active current
• 4kbits of EEPROM
—16-byte page write mode
—Self-timed write cycle
—5ms write cycle time (typical)
• Built-in inadvertent write protection
—Power-up/power-down protection circuitry
—Protect 0, 1/4, 1/2, all or 16, 32, 64 or 128 bytes
of EEPROM array with Block Lock™ protection
• 400kHz 2-wire interface
• 2.7V to 5.5V power supply operation
•www.DataSheet4U.com Available packages
—8 Ld SOIC
—8 Ld MSOP
—8 Ld PDIP
• Pb-free plus anneal available (RoHS compliant)
BLOCK DIAGRAM
DESCRIPTION
The X4043/45 combines four popular functions,
Power-on Reset Control, Watchdog Timer, Supply
Voltage Supervision, and Block Lock Protect Serial
EEPROM Memory in one package. This combination
lowers system cost, reduces board space require-
ments, and increases reliability.
Applying power to the device activates the power-on
reset circuit which holds RESET/RESET active for a
period of time. This allows the power supply and oscilla-
tor to stabilize before the processor can execute code.
The Watchdog Timer provides an independent protec-
tion mechanism for microcontrollers. When the micro-
controller fails to restart a timer within a selectable
time out interval, the device activates the
RESET/RESET signal. The user selects the interval
from three preset values. Once selected, the interval
does not change, even after cycling the power.
The device’s low VCC detection circuitry protects the
user’s system from low voltage conditions, resetting the
system when VCC falls below the minimum VCC trip
point. RESET/RESET is asserted until VCC returns to
proper operating level and stabilizes. Five industry stan-
dard VTRIP thresholds are available, however, Intersil’s
unique circuits allow the threshold to be reprogrammed
to meet custom requirements or to fine-tune the thresh-
old for applications requiring higher precision.
WP
SDA
SCL
VCC
Watchdog Transition
Detector
Data
Register
Command
Decode &
Control
Logic
VCC Threshold
Reset logic
Protect Logic
Status
Register
EEPROM Array
VTRIP
+
-
Watchdog
Timer Reset
Reset &
Watchdog
Timebase
Power-on and
Low Voltage
Reset
Generation
RESET (X4043)
RESET (X4045)
1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 1-888-468-3774 | Intersil (and design) is a registered trademark of Intersil Americas Inc.
Copyright Intersil Americas Inc. 2005. All Rights Reserved
All other trademarks mentioned are the property of their respective owners.
1 page  
X4043, X4045
PRINCIPLES OF OPERATION
Power-on Reset
Application of power to the X4043/45 activates a
Power-on Reset Circuit that pulls the RESET/RESET
pin active. This signal provides several benefits.
– It prevents the system microprocessor from starting
to operate with insufficient voltage.
– It prevents the processor from operating prior to sta-
bilization of the oscillator.
– It allows time for an FPGA to download its configura-
tion prior to initialization of the circuit.
When VCC exceeds the device VTRIP threshold value
for 200ms (nominal) the circuit releases
RESET/RESET allowing the system to begin operation.
Low Voltage Monitoring
During operation, the X4043/45 monitors the VCC level
and asserts RESET/RESET if supply voltage falls
below a preset minimum VTRIP. The RESET/RESET
signal prevents the microprocessor from operating in a
power fail or brownout condition. The RESET/RESET
signal remains active until the voltage drops below 1V.
It also remains active until VCC returns and exceeds
VTRIP for 200ms.
Watchdog Timer
The Watchdog Timer circuit monitors the microproces-
sor activity by monitoring the SDA and SCL pins. A
standard read or write sequence to any slave address
byte restarts the watchdog timer and prevents the
(RESET/RESET) signal going active. A minimum
sequence to reset the watchdog timer requires four
microprocessor intructions namely, a Start, Clock Low,
Clock High and Stop. (See Page 18) The state of two
nonvolatile control bits in the status register determine
the watchdog timer period. The microprocessor can
change these watchdog bits, or they may be “locked”
by tying the WP pin HIGH.
Figure 1. Watchdog Restart
.6µs
1.3µs
SCL
SDA
Start
WDT Reset Stop
EEPROM Inadvertent Write Protection
When RESET/RESET goes active as a result of a low
voltage condition (VCC < VTRIP), any in-progress com-
munications are terminated. While VCC < VTRIP, no new
communications are allowed and no nonvolatile write
operation can start. Nonvolatile writes in-progress when
RESET/RESET goes active are allowed to finish.
Additional protection mechanisms are provided with
memory block lock and the Write Protect (WP) pin.
These are discussed elsewhere in this document.
VTRIP Programming
The X4043/45 is shipped with a standard VCC thresh-
old (VTRIP) voltage. This value will not change over
normal operating and storage conditions. However, in
applications where the standard VTRIP is not exactly
right, or if higher precision is needed in the VTRIP
value, the X4043/45 threshold may be adjusted. The
procedure is described below, and uses the applica-
tion of a high voltage control signal.
Figure 2. Set VTRIP Level Sequence (VCC = desired VTRIP values WEL bit set)
WP VP = 15-18V
SCL
0 1 23 4 56 7
0 1 23 4 56 7
0 1 23 4 56 7
SDA
A0h 01h
00h
5 FN8118.1
September 30, 2005
5 Page 
X4043, X4045
Figure 8. Acknowledge Response From Receiver
SCL from
Master
1
Data Output
from
Transmitter
Data Output
from Receiver
89
Start
Acknowledge
X4043/45 ADDRESSING
Slave Address Byte
Following a start condition, the master must output a
slave address byte. This byte consists of several parts:
– a device type identifier that is ‘1010’ to access the
array and ‘1011’ to access the control register.
– two bits of ‘0’.
– one bit that becomes the MSB of the address.
– one bit of the slave command byte is a R/W bit. The
R/W bit of the slave address byte defines the opera-
tion to be performed. When the R/W bit is a one,
then a read operation is selected. A zero selects a
write operation. Refer to Figure 8.
– After loading the entire slave address byte from the
SDA bus, the device compares the input slave byte
data to the proper slave byte. Upon a correct compare,
the device outputs an acknowledge on the SDA line.
Word Address
The word address is either supplied by the master or
obtained from an internal counter. The internal counter
is undefined on a power-up condition.
Slave Address Byte
Figure 9. X4043/45 Addressing
Slave Byte
Array
10 10
Control Reg. 1 0 1 1 0 0 A8 R/W
Word Address
A7 A6 A5 A4 A3 A2 A1 A0
Operational Notes
The device powers-up in the following state:
– The device is in the low power standby state.
– The WEL bit is set to ‘0’. In this state it is not possi-
ble to write to the device.
– SDA pin is the input mode.
– RESET signal is active for tPURST.
SERIAL WRITE OPERATIONS
Byte Write
For a write operation, the device requires the slave
address byte and a word address byte. This gives the
master access to any one of the words in the array.
After receipt of the word address byte, the device
responds with an acknowledge, and awaits the next
eight bits of data. After receiving the 8 bits of the data
byte, the device again responds with an acknowledge.
The master then terminates the transfer by generating a
stop condition, at which time the device begins the inter-
nal write cycle to the nonvolatile memory. During this
internal write cycle, the device inputs are disabled, so the
device will not respond to any requests from the master.
The SDA output is at high impedance. See Figure 10.
A write to a protected block of memory will suppress
the acknowledge bit.
11 FN8118.1
September 30, 2005
11 Page | ||
| Páginas | Total 24 Páginas | |
| PDF Descargar | [ Datasheet X4045.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| X40410 | (X40410 - X40415) Dual Voltage Monitor | Intersil Corporation |
| X40411 | (X40410 - X40415) Dual Voltage Monitor | Intersil Corporation |
| X40414 | (X40410 - X40415) Dual Voltage Monitor | Intersil Corporation |
| X40415 | (X40410 - X40415) Dual Voltage Monitor | Intersil Corporation |
| Número de pieza | Descripción | Fabricantes |
| SLA6805M | High Voltage 3 phase Motor Driver IC. |
 Sanken |
| SDC1742 | 12- and 14-Bit Hybrid Synchro / Resolver-to-Digital Converters. |
 Analog Devices |
|
DataSheet.es es una pagina web que funciona como un repositorio de manuales o hoja de datos de muchos de los productos más populares, |
| DataSheet.es | 2020 | Privacy Policy | Contacto | Buscar |