replacing chips

[Srigopal007]

I have previously used a 8051 microcontroller to perform most if not all of my processing needs. I have recently been introduced to the Microchip PIC microcontrollers. I was wondering if it is possible to replace the entire 8051 chip and have the PIC do the same exact things. Is it possible to entirely replace the 8051 chip and have the PIC do all of the processing work for me. Are there any timing issues or r/w issues that I might encounter if I do this.

srig

[mister_e]

IMHO everything is possible. PIC will do more than those stupid unusefull 'stone age industry standard' chips. i can't remind how many Z80 and 8051 board based i upgrade with PIC. I replace those using a 'Mister's 8051 to PIC' adapter. BUT if you want to have a direct replacement pin-to-pin Atmel do some like the AT89C51

Since you know what every i/o do... you can't have any kind of problems.

[Dwayne]

Hello Srigopal,

s>>I have previously used a 8051 microcontroller to perform most if not all of my processing needs. I have recently been introduced to the Microchip PIC microcontrollers. I was wondering if it is possible to replace the entire 8051 chip and have the PIC do the same exact things.<<

Definitely... the 80C51 microprocessors are what I used to program. Personally the PICS are a heck of a lot cheaper, nicer to work with, and IMO just as solid or even more.

Since the pin count is different than, and the VSS and VCC are different, I seriously doubt if there is a direct "PLUG-IN" chip that will match up.

I think I still have a dozen or so 750's and 752's , programmer, and emulator I don't know what I am going to do with <g>

Dwayne

[mister_e]

He dwayne


Definitely... the 80C51 microprocessors are what I used to program. Personally the PICS are a heck of a lot cheaper, nicer to work with, and IMO just as solid or even more.


personally, i consider those micro as stupid as Basic Stamp can be. Nothing to do with those without adding extra external device for A/D or else we often need



Since the pin count is different than, and the VSS and VCC are different, I seriously doubt if there is a direct "PLUG-IN" chip that will match up.


No there's not Microchip PIC that will directly fit, you must do one adapter.


I think I still have a dozen or so 750's and 752's , programmer, and emulator I don't know what I am going to do with

open a museum !

[Dwayne]

Hello Steve,

Steve>>I think I still have a dozen or so 750's and 752's , programmer, and emulator I don't know what I am going to do with <<


Think I should sterilize them with UV, before displaying them? <g>, I would hate to have them interbreed with the PIC of the crop Micro-chips, causing MCLRs, bitty problems, and resets.

[Srigopal007]

I hope this is not a stupid question! and I konw it all depends on the applications that I am going to be working with, but what PIC should I look into that might be nearly a close fit to the 8051?

srig

[mister_e]

You must choose a PIC who'll provide you at least the code space you need and the i/o you need.

In case you need about the same i/o than the 8051 have... PIC16F870,16F877 or else PIC that have close to 32,33 i/o with sufficient code space.

[Dwayne]

Hello Srig,

Srig>>I hope this is not a stupid question! and I konw it all depends on the applications that I am going to be working with, but what PIC should I look into that might be nearly a close fit to the 8051? <<

No it is not...The main quesiton is, which 8051 based microchip are you using? there are about 100 of them. My favorite were the 752's and 750's. They were the cheapest, yet the coding was exactly the same for both.

Maybe a more accurate question would be:
What project are you attempting to do? and what requirements are needed to make that project work?

For example, we can use a 40 pin PIC and make it work a LCD and AD, producing a complete project for a temperature warning system. But wouldnt a 18 PIN PIC with AD and PORTB do the same job with 1/4 the size and cost? Does your project need ADC?, PWM?, or comparators? Some PICS do not have 1 or 2 of these basic things, but they may have I2C, USARTs, and other items of interest.

Dwayne

[Srigopal007]

Hi forum, I have used an Intel 8051 microcontroller for a project to control a few leds from some ports. This project was done some time ago and I want to upgrade the existing design with a microchip PIC. I was hoping to get some assistance on what chips are pausible or almost exact replica of the 8051 uController. The 8051 has four ports Port0-Port3. and I am planning to use the PIC16F77 as the microcontroller of choice. Here is some information of the Intel 8051 chip:

-Port0 is a 8 bit Open Drain bidirectional I/O port. this port is also the multiplexed low order address and data bus accessing to external Program and Data Memory. (For example: Where is this located in the PIC16F77)

-Port1 is a 8 bit Bidirectional I/O port with internal pullups (This is similar to PortB in the PIC16F77)

-Port2 is a 8 bit bidirectional I/O port with internal pullups. And also it emits the high order address byte during fetches from external Program Memory and Accesses the Data memory

-Port3 is a 8 bit bidirectional I/O port with internal pullups. And it has the serial communication features connected to this port (This can be similar to PortC in the PIC16F77)


The confusion which I'm having is how do I lay out my Boards so that the connection of the PIC is 1-to-1 with the 8051. I think that I have the correct connection of the 8051's Port1 and Port3 conncting to PortB and PortC in the PIC correct, respectively. But I"m having a hard time trying to figure out how Port0 and Port2 which are the low and high bytes relating to DATA and Address memory can be correlating to any of the PortA or PortD of the PIC. since these are the only ones which are available to me becasue Port1 and port3 are occupied by PortB and PortC, respectively. I hope that I am making some sense for anyone to help me. Any help to reduce the confusion would be greatly appreciated. Thanks in advance.


srig