[sdiy] HMI-200 8051 ICE Ext. Clk

[Tony K]

Not sure why this didn't get through.

> On Oct 12, 2016, at 10:49 PM, Tony Kalomiris <weplar at gmail.com> wrote:
> 
> I have been studying the clock circuit of both the HMOS and CHMOS devices and according using the Intel 8-Bit Embedded Controllers handbook (1990), along with the App-155 "Oscillators for Microcontrollers".
> 
> The bit (no pun intended) I'm confused about is how that POD bypasses the onboard crystal/resonator.
> Does it just ground the input (Xtal2) and drive the output (Xtal1) for the HMOS device. In other words leaves the reactive components sitting across the output. 
> 
> The internal processor of the emulator is an 80C154 a superset of the 8051/8031 etc.
> Oh and the cabling is roughly 16" long, not much longer than the internal wiring in the synth.
> I will try this on breadboard circuit next. Wonder how other ICE's documentation deal with this 'dangling' crystal on the target.
>