Atmel C51 Datový list

Design Guide for Atmel’s C51 Standard DevicesIntroductionThe aim of this document is to help customers to avoid errors that are frequently done in ord

107764A–8051–11/07 1.3 Oscillator circuitThe on-chip oscillator is composed of a single-stage inverter and a parallel feedback resistor. The XTAL1 an

117764A–8051–11/07 1.3.1 Test conditionsIt is recommended to monitor the clock on XTAL2 pin. Special care must be taken when measuring XTAL1 signal.

127764A–8051–11/07 1.3.3 Overtone crystalsProblem: Sometimes overtone crystals are used with a standard oscillator circuit where a spe-cific one is r

137764A–8051–11/07 1.4 Microcontroller statusDuring hardware or firmware debugging, it is sometimes interesting to know what the state of the microco

147764A–8051–11/07 2. In-System Programming (ISP)The In-System Programming feature will be referenced as ISP in the rest of the document.Most of Atme

157764A–8051–11/07 Figure 2-1. HPC hardware condition2.2 LPC package2.2.1 Hardware settingsThere are no specific hardware settings to apply.2.2.2 Sta

167764A–8051–11/07 Figure 1. Low Pin Count regular boot processHardware condition: when the BSB is inactive, the only way to have the device run in

177764A–8051–11/07 Figure 2-2. LPC hardware condition2.3 Using the ISP mode over RS232 interface2.3.1 BaudrateThe maximum baudrate supported by the d

187764A–8051–11/07 DTRRx_PCCTSDSRTx_MCURx_MCUTx_PCRTSVccVccVccVccVccVccVccVccVcc/PSENP3_0/RxDP3_1/TxDRSTAUTO ISP FEATURERS232 INTERFACEC25100nC25100n

197764A–8051–11/07 3. Troubleshooting3.1 MCU not starting or operating in a reliable wayPossible root cause I/O External Code Internal CodePOWERS and

27764A–8051–11/07 1. Basics of ATMEL’s C51 Standard devices1.1 Program memory configurations1.1.1 ScopeFigure 1-1. Code fetched from external program

207764A–8051–11/07 3.2 In-System Programming does not workPossible root cause External Code Internal CodeMCU is not working in ISP modeNOT APPLICABLE

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37764A–8051–11/07 1.1.2 Type of packageIn most of the products, two kind of packages are proposed: the HPC (High Pin Count) and the LPC (Low Pin Coun

47764A–8051–11/07 Figure 1-3. Reset bock diagramWatch DogRSTInternal ResetTimerMicrocontrollerVccC51CorePORPFDTable 1-2. Features descriptionsFeature

57764A–8051–11/07 Figure 1-4. Behaviour of POR and PFDVCoretInternalVPFDPVPFDM10PORPORPFDResetActiveNot active

67764A–8051–11/07 1.2.2 How to drive the RST pin according to the features implemented on the deviceThis procedure is only applicable to Active High

77764A–8051–11/07 b) Using an external Brown-out deviceRead application note “External Brown-out Protection for C51 microcontrollers with Active High

87764A–8051–11/07 1.2.2.2 POR implementedWhen the POR is implemented, the use of external components is optional. The RST pin may be left unconnected

97764A–8051–11/07 c) Using an external Brown-out deviceRead application note “External Brown-out Protection for C51 microcontrollers with Active High