Strange chips

dmitrboristuk · Joined: 26 Sep 2020 Posts: 55

In the lists of devices supported by the compiler CCS there is such a device as PIC16C99, but does it exist in reality?
I also have a question in the lists of devices produced by Microchip there is such a device as MTR6618. It is sold in Asian markets, but anywhere in the network has no datasheets. What's the deal here?

Ttelmah · Joined: 11 Mar 2010 Posts: 19504

The C99, existed years ago. However I doubt if any have been sold for at
least a decade. I used it back in the 1990's. Same comment will apply as
for the MTR. Not sure without checking, but I think it was OTP ROM based,
not flash. It was also almost impossible to use, since it had so little stack...
The key on the MTR6618, is it is not available in a Rohs compliant version.
It was made for a specific client, possibly for a Rohs exempt application, so
cannot be sold into 90% of the world markets unless the application has
such an exemption.

dmitrboristuk · Joined: 26 Sep 2020 Posts: 55

Thank you for your reply. I believed that the oldest devices were PIC14000 and 81010. It's just that it is impossible to find datasheets for C99 and MTR6618 on the network. Datasheets are available for devices from 1993-1997, but these devices are not.
According to some information, MTR6618 is a common PIC18f67J10, possibly with distinctive features.

Ttelmah · Joined: 11 Mar 2010 Posts: 19504

The first PIC, was the PIC1650, designed by General Instruments. In 1975.
The PIC16C84, was the first one I used at the end of 1992. Microchip
themselves claim it didn't come out till 1993, but I have PCB designs I did
using it in 1992!... I'd guess these were engineering sample chips. I did
point this out to them, but they said their date is when it became officially
available....
Data sheet dates can be misleading, since they have often been revised.
There are also some other oddities. I have a paper data sheet for a 16C24.
However I don't think this was ever released.
The 14000, was the first PIC 'targeted' at handling analog stuff. It had
a comparator and a current source, allowing you to build what could
actually be a 16bit ADC (though accuracy was nowhere near this). I think
it was the first one that referenced 'mixed signal'.