replacing chips

[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