Sat Aug 9 10:07:51 BST 2008
Microchip programming protocol
Towards a zero-cost standard platform for Microchip PIC. All PICs
support the microchip programming protocol, consisting of:
1 /MCLR Vpp
( see http://www.prc68.com/I/ICD2.shtml )
PICs without charge pump need 13V Vpp and can't program themselves.
It is necessary to split the development workflow into two parts:
* Single chip applications: this can use a combined full programmer
+ debug monitor to also support chips that need Vpp. This is the
one useful for teaching, so it makes sense to make the tethering
hardware as simple as possible, i.e. to not depend on a Microchip
* Networked applications: here interconnect needs to be as simple as
possible, so the 5-wire programmer protocol is impractical. Cost
of tethering hardware isn't critical, so can have more complexity.
It's best to stick with something standard here, i.e. I2C or CAN
bus. The topology can be symmetric: programmer host interface can
be just one of the nodes.