8051 and ARM microcontrollers

The microcontroller type I have mostly used is a derivative of the Intel 8051 microcontroller. There are several free and commercial C and Assembler compiler on the market. To name a few I can mention these

I have used Sdcc and ASEM-51 myself. Sdcc is a C compiler and now I have stopped using Assembler except for very simple time demanding codes. The assembler code for Sdcc and ASEM-51 is unfortunately not compatible.

Raisonance and Keil are expensive integrated development environments that have free trial version. However, these are exclusively Windows programs.  I have run both Raisonance and Keil under Wine but it was problematic. I will test again and write about the result.

8052 is a derivative or an enhanced version of the Intel 8051 version with extra hardware like larger RAM, extra timer, hardware UART or I2C bus. There are many different versions of the 8051 with different addons.

I have mostly used the P89C668 version from NXP (former Philips semiconductors). This particular version is not recommended for new designs but all the information is applicable to for example the P89V664 wich has 2KB of RAM instead of 8KB.

To upload programs I use my own simple utility called progphil. Currently only the P89C66x controllers are supported. 

ARM microcontroller

I bought an LPC-2148-R2 development board from Olimex. It is a surplus production, marked IAR. I got the IAR CD with the package but no  JTAG connector with it. I did not find out how to use the IAR tools without a JTAG connector and so far I cannot afford one nor the IAR tools. Therefore I shifted to the Open Source tools.

The development is powered by the computers USB cable (you have to change a jumper setting). The serial cable is used to program the device.

The best thing to start with is the following page. There is a thorough description from Bdale Garbee on how to install the gcc compiler for ARM devices on Debian. The same description with minor changes can be found here. I don't use sudo and there are new versions of the tools available.

The source code can be downloaded with the command line program lpc21isp. You have to join the group to be able to download the program.

To program the device do the following: Move the blue switch to "ON", then press the small (reset) button above and then use the following command to upload the program file:

$ lpc21isp -control test.hex /dev/ttyS0 <baud rate> <clock crystal in kHz>

The -control option is needed. I haven't been able to run the program with higher baud rate than 38400. I have tested it with 9600, 19200, 38400 but it doesn't work with 57600 and above. To run the program, move the switches to "OFF" position and then press the reset button again.

I found some example programs at the Olimex homepage, that I cannot find anymore and did not compile with gcc but they could be changed quite easily. I made a tar file with three example programs.  The following programs are supplied:
It contains the following files

To compile the program just type
$ make
To install it, put both blue switches to ICPS. Then press RST and finally run
$ lpc21isp -control main.hex /dev/ttyS0 38400 12000
Move the switches to RUN and open a terminal program like gtkterm. There is a problem with gtkterm. It cannot read '\0' and if it gets a '\0' input, then the following bytes may be scrambled.

Writing a makefile isn't as simple as for normal Linux programs since a linker script must be written. The linker script must contain information about the memory layout of the microcontroller. The original linker script from the Olimex source fails when using the sprintf function.

Now I have bought an LPC-H2148 header board from Olimex and an ARM-USB-TINY-H, high speed JTAG connector. There is an open usbstack at sourceforge called lpcusb that works nicely on the lpc2148. There was a wiki page attached to it but it has been down for some time. I recommend that you get the svn version:
svn co https://lpcusb.svn.sourceforge.net/svnroot/lpcusb lpcusb
because it contains a benchmark program for the. It can be compiled on Debian with the following makefile (I have renamed the c file from main.c to benchmark.c).
You need to install libusb-dev, apt-get install libusb-dev.
Uwe Hermann has packaged openocd for Debian (many thanks), he also has good explanations on how to set upt the arm toolchain on Debian/Ubuntu.
apt-get install openocd.
I managed to program my device with the following command:
$ openocd -f lpc2148.cfg -f olimex-arm-usb-tiny-h.cfg -c init -c "mt_flash custom.hex"
where olimex-arm-usb-tiny-h.cfg is the original file from openocd but lpc2148.cfg is slightly changed.

The programming ends with a lot of error messages but it works and the output of the benchmark program is:
# ./benchmark
Testing blocksize    64
* read :   95872 bytes in 3001 ms = 31 kB/s
* write:   96000 bytes in 3001 ms = 31 kB/s
Testing blocksize   128
* read :  192000 bytes in 3002 ms = 63 kB/s
* write:  192128 bytes in 3002 ms = 64 kB/s
Testing blocksize   256
* read :  383744 bytes in 3002 ms = 127 kB/s
* write:  384256 bytes in 3002 ms = 128 kB/s
Testing blocksize   512
* read :  767488 bytes in 3002 ms = 255 kB/s
* write:  768000 bytes in 3002 ms = 255 kB/s
Testing blocksize  1024
* read : 1026048 bytes in 3001 ms = 341 kB/s
* write: 1026048 bytes in 3001 ms = 341 kB/s
Testing blocksize  2048
* read : 1048576 bytes in 2046 ms = 512 kB/s
* write: 1048576 bytes in 2046 ms = 512 kB/s
Testing blocksize  4096
* read : 1048576 bytes in 1540 ms = 680 kB/s
* write: 1048576 bytes in 1540 ms = 680 kB/s
Testing blocksize  8192
* read : 1048576 bytes in 1406 ms = 745 kB/s
* write: 1048576 bytes in 1406 ms = 745 kB/s
Testing blocksize 16384
* read : 1048576 bytes in 1335 ms = 785 kB/s
* write: 1048576 bytes in 1335 ms = 785 kB/s

By the way. You need to run the program as root but by adding a lpc2000.rules file to /etc/udev/rules.d it can be run if by members of the iocard group.

Last modified: 2010-05-16