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glossary:glossary_i [2020/05/08 06:13] – [ICs] tgerbicglossary:glossary_i [2023/07/25 15:55] (current) – [ISR] add ISTR entry JohnFletcher
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-===== ICSP =====+===== ICSP (In Circuit Serial Programming) ===== 
 + 
 +ICSP is a means whereby embedded microprocessors are 'programmed' (having their machine code loaded) while mounted in the circuit they are intended to control. 
 +There are no standard physical designs/pinouts used for ICSP. \\ 
 +Generally MERG modules, with PIC microprocessors, are provided with a 6 way (1 pin omitted) ICSP connector used with a 'twist' cable to a Microchip PICKIT programmer. 
 +[[:helpsystem:pickit2cbus|MERG PIC ICSP cable pinout shown here.]]\\ 
 +Arduino modules use a USB connection.\\ 
 +AVR ATMEGA chips use a 6 pin connector based on SPI bus. (Optional on Arduino AVR modules)\\ 
 +Atmel SAMD chips have a OneWire ICSP (signal/0v/power). 
  
-In Circuit Serial Programming is a means whereby microprocessors (PICs and other types), may be programmed while mounted in the circuit they are intended to control. There are no standard physical designs/pinouts used for in-circuit programming. Many MERG modules using PIC microprocessors are provided with an ICSP connector with a pinout for the popular PICKIT programmer.\\ 
-[[:helpsystem:pickit2cbus|Pinout shown here.]]\\ 
  
 ===== Incandescent lamps ===== ===== Incandescent lamps =====
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  \\ [[http://www.kpsec.freeuk.com/components/lamp.htm|http://www.kpsec.freeuk.com/components/lamp.htm]]  \\ [[http://www.kpsec.freeuk.com/components/lamp.htm|http://www.kpsec.freeuk.com/components/lamp.htm]]
 +
 +
 +===== Include Guard =====
 +
 +A method of preventing a C or C++ header source file (.h or .hpp), from being included more than once by other files. It uses 'compiler directives' ''#'' to do this.
 +
 +''#ifndef _FILENAME_H_''
 +
 +''#define _FILENAME_H_''
 +
 +''/ contents of the header file go here */''
 +
 +''#endif /* _FILENAME_H_ */''
 +
 +If the compiler supports it, then following can be used
 +
 +''#pragma once''
 +
 +''/ contents of the header file go here */''
 +
  
  
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-Description used by UK track manufacturer, PECO, to denote turnouts manufactured with an insulated crossing (frog). This avoids the need for polarity switching for the crossing at the expense of poorer current collection for locomotives.+Description used by UK track manufacturer, PECO, to denote turnouts manufactured with an insulated common crossing, AKA frog. This avoids the need for polarity switching for the crossing at the expense of poorer current collection for locomotives. AKA dead frog.
  
  
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 =====ISR===== =====ISR=====
  
-An Interrupt Service Routine is a firmware/software program subroutine (sub-program) triggered by a microprocessor hardware pin. When triggered, the processor will temporarily execute a subroutine then return to the previous program execution. An ISR can be used to make the processor immediately take care of a time critical operation. While there are many uses for an ISR, some common uses would be for receiving serial bits from a serial data interface or sensing an external clock signal to trigger the sending of video signals at a precise time. In some cases there are more than one interrupt trigger pin or indication. Because of this there may be priority settings. A High priority interrupt cannot itself be interrupted whereas a Low priority interrupt can be interrupted by a High level one. This helps keep multiple ISRs from interfering with each other. +An Interrupt Service Routine is a firmware/software program subroutine (sub-program) triggered by a microprocessor hardware pin. When triggered, the processor will temporarily execute a subroutine then return to the previous program execution. An ISR can be used to make the processor immediately take care of a time critical operation. While there are many uses for an ISR, some common uses would be for receiving serial bits from a serial data interface or sensing an external clock signal to trigger the sending of video signals at a precise time. In some cases there are more than one interrupt trigger pin or indication. Because of this there may be priority settings. A High priority interrupt cannot itself be interrupted whereas a Low priority interrupt can be interrupted by a High level one. This helps keep multiple ISRs from interfering with each other
 + 
 + 
 +=====ISTR===== 
 + 
 +I seem to recall....
glossary/glossary_i.1588918409.txt.gz · Last modified: 2020/05/08 06:13 by tgerbic

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