Author Topic: M9S12NE64 - Welcome  (Read 4108 times)

Offline mark

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M9S12NE64 - Welcome
« on: July 09, 2007, 09:09:09 PM »
Hi All

The M9S12NE64 is an HCS12 derivative which first became available towards the end of 2004.
In fact this is exactly the chip which I was looking for to start a new embedded project with Ethernet support and fortunately it turned up at the time that I started looking.

The uTasker software was developed initially for this chip and with this chip. This was an interesting experiment since I wanted to see whether it would be possible to develop a TCP/IP stack from scratch using a new chip and the GNU compiler with my own debugging tools (which also had to be developed). It is fortunate that the DEMO9S12NE64 which I bought is delivered with a serial monitor program installed and that this program is documented in an application note from Freescale; it allowed a simple PC program to be written which could load code to FLASH, read and write memory and registers as well as set a break point before single stepping. In addition to that, it was necessary to understand the operation of the chip and its instruction set, but this forces learning quite a few important details.

Using a PSA (Pseudo-Assembler) file generated by the GNU compiler together with simple assembler level code stepping it was possible to get first simple programs to run but it was clear that this would be inadequate for more complex debugging jobs so this is where the uTasker simulator came in. In fact the simulator was not something completely new since I did have a forerunner of it which was pieced together for use in various projects, for example for the 8051 and for the LPC2106 to name a couple, but it was time to pull it together as a part of a new development environment. The dream that I had was to be able to get advanced information on new chips (specifically Ethernet controllers) and program up the simulator so that the not-yet-existant part could be programmed for. And indeed, working with data from Ethereal recordings, first steps were made to develop a TCP/IP stack integrated closely with the uTasker operating system.

The simulator worked well enough to enable the development of the first uTasker version for the NE64 with its drivers, file system and TCP/IP stack, using nothing more that the simple downloading, debugging tool (ne64_deb.exe as delivered with the uTasker for the NE64). Later a BDM project was added - this can be found on the web site under documents (projects and application notes). The present NE64 package includes Codewarrior 4.5 and IAR projects too.

It was however not until early 2006 - when the uTasker V1.2 was made available - that the simulator took on its present appearance and supported true Ethernet support via the PC's NIC. This was thanks to Joel W. who helped get the WinPCap bits to work together with it. In fact when I look back, I still find it hard to believe that the stack was developed before this stage - it would probably have been much easier now.

Although the NE64 is a neat chip - I still do projects using it and it is surprising how popular it still is!! - Freescale will probably  not further develop it in the future. Its big-brother, the M5223X is probably the long term solution of preference. Nevertheless the NE64 is still possibly the cheapest solution for small embedded Internet capable projects and it has earned its place in the uTasker project and will receive continued support.

Please use this forum section for all to do with the NE64.
I look forward to reading your topics.



« Last Edit: July 10, 2007, 09:34:22 PM by mark »