Nicholas Winterer

MON08 Programmer

Discussion created by Nicholas Winterer on Apr 9, 2006
Latest reply on Apr 11, 2006 by David Payne
First of all, I'm new to this whole microcontroller thing, so get ready for a lot of dumb questions asked in a short amount of time.

I built the monitor mode circuit from Application note 2317, and have used it to program a couple of GP32s to blink LEDs and the like. The problem is that I don't really know what i'm doing and the monitor mode circuit is integrated into the circuit that my micro controls. I was planning on building a PCB with the monitor mode circuit from AN2317 and just mounting a header on that board to use for ISP, but first i have a few questions.

1. How does someone typically add an ISP interface to a target circuit? Would i have to sacrafice the PTA0, IRQ, and other pins that are needed to bring the MCU into monitor mode? If not, how do people avoid things like short circuits, do they have a way of disconnecting the target device from the circuit it controls?

2. Should my programmer board provide power to the target, or does the target pwoer itself. If are powered by different power supplys, could that pose a problem with different ground potentials?

3. Should my programmer provide the 9.8304 MHz clock to the target? Also, how do you set an HC08 to run of it's internal clock, as my devices have a tendancy to quit working whenever i disconnect the programmer?

Basically I would like to know how people lay out the headers on thier programmers and how they handle things such as the signals on portc when the controller is starting up to bring it into monitor mode.

Sorry for the dumb questions and thanks for any help!