At89c4051 Monitor

[Joe de Beer]

I need a "monitor program" to develop small programs for the above microprocessor. Basically what I am looking for is software smaller than 4KB (to fit inside the 89C4051 EEPROM) enabling me to communicate via RS232 with a Windous PC (hyperterminal) and hence develop and store assembler programs in external RAM for later use in a stand alone board. I am not sure what such a monitor program is called (emulator, simulator embedded assembler????). If someone can help me with a schematic and software I would be most grateful!
Joe

 

[Papabravo]

You are aware that program memory space and data memory space in the 8051 architecture are separate memory spaces. Programs will not execute from internal RAM. Using external memory you need to have memory which is colocated in program memory space and data memory space. You do this by combining PSEN* and RD* to read data from the external memory.

Sorry to rain on your parade.

 

[Joe de Beer]

Thanks PB. I don't mind the rain. Where I live, rain is always welcome! Thanks for reminding me about the separation of internal RAM and internal eeprom memory. My thinking was that one could use internal eeprom to store a program (my "monitor program", residing inside the 4051 with start address 0000 and being smaller than 4KB) which, when the uP resets and start executing from adress 0000, would do the necessary initialising and start communicating with my PC enabling me to develop my own pgm directly in assembler (hex machine code - not mnemonics), store it in external RAM (made nonvolatile by battery backup) for transporting to a separate board. In this process the "monitor program" can of course branch to internal 128 byte RAM for temporary storage of variables and constants. This "monitor program" should enable me to interactively write my own little pgm using the PC's keyboard.

 

[Nigel Goodwin]

I think you're really looking at the wrong century?, monitor programs like that were 1980's micro-processor techniques - things have moved on vastly since then. All the tools you need for micro-controllers are freely available, and many have "in-circuit debugging", "in circuit programming" and "boot-loaders" which render a monitor program pointless.

 

[Mike - K8LH]

Brings back very fond memories of the feature packed Apple ][ monitor with its mini-assembler and mini-disassembler and the Motorola 68HC11 BUFFALO monitor. I added commands and code to BUFFALO to program EPROMs and EEPROMS at one time.

Anyway, I've always thought it might be kinda' cool to install a simple monitor and Integer BASIC interpreter in firmware on a PIC and run tokenized programs out of RAM or EEPROM.

 

[Joe de Beer]

Thanks Nigel. Your comments are appreciated. You are right of course about the wrong century. My wife always thinks I am behind the times! I am aware of the Pic situation. The AT89C4051 is not a PIC though and information about it is not so freely available. I will surf a bit more and see what comes up. Thanks for your comments.

 

[Sceadwian]

Mind you Atmel also makes a line of 8bit micro controllers. Their Mega and tiny series processors are very very nice.

 

[Nigel Goodwin]

Thanks Nigel. Your comments are appreciated. You are right of course about the wrong century. My wife always thinks I am behind the times! I am aware of the Pic situation. The AT89C4051 is not a PIC though and information about it is not so freely available. I will surf a bit more and see what comes up. Thanks for your comments.

The PIC is the most popular micro-controller, but there's still plenty of information about other ones as well, with Atmel probably coming second in the popularity stakes?.

 

[Sceadwian]

AVR's have some serious I/O and raw calculation performance advantages that shouldn't be overlooked, popularity aside.

 

[Nigel Goodwin]

AVR's have some serious I/O and raw calculation performance advantages that shouldn't be overlooked, popularity aside.

PIC's have other advantages though, and the higher end PIC's equal or better the performance of AVR's anyway - but in the vast majority of cases (99%+?) speed isn't an issue.