u5021m ATMEL Corporation, u5021m Datasheet
u5021m
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u5021m Summary of contents
Page 1
... Enable Output 1. Description The digital window watchdog timer, U5021M CMOS integrated circuit. In applica- tions where safety is critical especially important to monitor the microcontroller. Normal microcontroller operation is indicated by a cyclically transmitted trigger signal, which is received by a window watchdog timer within a defined time window. ...
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... Figure 1-1. Block Diagram with External Ciruit OSC Reset 5 Micro- controller 2 Trigger 3 Mode 1 Wake-up 2. Pin Configuration Figure 2-1. Pinning SO8 U5021M Oscillator OSC State machine OSC Input signal conditioning Power-on POR POR reset 7 GND 1 WAKE-UP 2 TRIG ...
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... Supply voltage 7 GND Ground, reference voltage 8 OSC RC oscillator 4. Functional Description 4.1 Supply Voltage, Pin 6 The U5021M requires a stabilized supply voltage V characteristics. An external buffer capacitor may be connected between pin 6 and GND. 4.2 RC Oscillator, Pin 8 The clock frequency, f, can be adjusted by the components where ...
Page 4
... The switch-over mode time enables the synchronous operation of microcontroller and watchdog. When the power-on reset time has elapsed, the watchdog has to be switched to monitoring mode by the microcontroller by a “low” signal transmitted to the mode pin (pin 3) within the time-out period, t erates a reset pulse, t the switch-over mode time, t U5021M 4 = 500 ...
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... The positive edge of the trigger signal , (enable time). The 3 2 Pin 6 Pin Pin 3 Pin ensure correct operation of the micro and an enable time which a trigger sig U5021M 5 ...
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... Wake-up Mode Trigger Enable 5. State Diagram The kernel of the watchdog is a finite state machine. possible states and transmissions. Many transmissions are controlled by an internal timer. The numbers for the time-outs are the same as on the pulse diagrams. U5021M shows the switch-over from the short to the long watchdog mode ...
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... Short window disable state time out t 2 trg_ok = 1 mode = 1 Short window enable state time out t 3 trg_err = 1 trg_err = 1 time out wedge = 1 mode = 1 Long window disable state mode = 0 time out t 4 trg_ok = 1 mode = 0 Long window enable state trg = 0 or wedge = 1 U5021M 7 ...
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... Logical “high” Logical “low” Hysteresis Input voltage range Input current Input current Outputs Maximum output current Logical output “low” I OUT Logical output “high” I OUT Leakage current V OUT U5021M 8 Symbol OUT amb T stg Symbol R thJA Pin ...
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... Remarks Tubed, Pb-free Taped and reeled, Pb-free 5.2 4.8 3.7 0.2 3.8 6.15 5.85 technical drawings according to DIN specifications U5021M Max. Unit Cycle 128 Cycle Cycle Cycle Cycle Cycle Cycle Cycle Cycle Cycle 9 ...
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... Please note that the following page numbers referred to in this section refer to the specific revision mentioned, not to this document. Revision No. 4756D-AUTO-11/05 4756C-AUTO-09/04 4756B-AUTO-07/04 U5021M 10 History Put datasheet in a new template First page: Pb-free logo added Page 7: figure 5-1 changed Page 9: Ordering Information changed Electrical Characteristics Table, page 8, row “ ...
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... Atmel products are not suitable for, and shall not be used in, automotive applications. Atmel’s products are not intended, authorized, or warranted for use as components in applications intended to support or sustain life. © Atmel Corporation 2005. All rights reserved. Atmel marks or trademarks of Atmel Corporation or its subsidiaries. Other terms and product names may be trademarks of others. Atmel Operations Memory ...