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Most of ARM programmers come with BSL,RESET,TXD, RXD, GND and VCC pins which we need to connect with respective pins of ARM.

For ISP, We require need to ground P0.14/BSL after Reset.

As these programmers have Both BSL and RESET pins, Does programmer itself Resets controller and pulls BSL to ground OR do I need to first pull BSL to ground, Reset controller and then start programming using softwares like FlashMagic?

Also, Does ARM remains in Bootloader if I pull P0.14/BSL to ground after power up till next reset or does it have any sort of time out that it will jump to application code after that.

Or as Wouter van Ooijen rephrased it, whether the bootloader will spontaneously jump to the application after a certain timeout?

I am working with LPC2138.

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  • \$\begingroup\$ You are confusing the ARM core with some specific microcontroller you neglect to mention. \$\endgroup\$ – starblue Dec 22 '12 at 20:19
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As starblue points out, you are referring to the LPC range of microcontrollers. Mentioning this in the title and/or text of your question is advisable.

Whether the programmer pulls BSL low for you (and also whether it resets the chip for you!) depends on the programmer and the PC software you use.

FlashMagic and lpc21isp can be configured to do both for you, provided of course that the programmer hardware (which can be as simple as an FT232RL chip) supports this and is connected to the target correctly.

I cannot make sense of your last question. Maybe you want to know whether the bootloader will spontaneously jump to the application after a certain timeout? AFAIK not.

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The boot loader in the controller samples the pin(s) which decide whether to enter the boot loader shortly after reset. Once it has entered the boot loader there is no timeout and you have to reset the controller again to start the application.

Note that the pin(s) used may differ depending on the specific series of controllers (e.g. for LPC11xx the pin for entering the boot loader is P0_1).

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