Please let me know the procedure for below
I am new for this design. I would like to know how to interface 4 SRAMs of 32 K bytes to 8051 microcotroller and I am developing code in C language in C51 Keil compiler.
Cy62256-SRAM 11.0592MHZ crystal
Requirements is to use 3x8 decoder. Why? Is it a school job?
no no, I am new to this field so, I am trying to interface like this way. so, just I said like this is my requirement
What Language are you writing the code with? A generic 8051 only supports 64K of RAM. So you will have to use another port pin to address 128K. The code will then have to insure the correct memory is selected. In this case a 3 to 8 decode will work. What is the part number of the chip you are using? Does it support 128K directly?
What beginner's 8051 project requires 128K RAM?!
Instead, perhaps you should begin with the basics - and just interface one of those RAM chips?
When you've mastered that, try two RAM chips - which will fill the standard 8051's 64K XDATA address space.
Only then should you consider moving on to extending the XDATA space beyond 64K.
In fact, these days, you should be seriously asking yourself whether it's worth the effort of trying to extend the 8051 beyond its limits at all! If you know you will need more memory than an 8051 can support, why even start with an 8051?!
See: www.8052.com/.../read.phtml
Q: Is it a school job?
A: no no
So what, exactly, is the objective of this exercise?
With 32-bit processors almost for free, I would not spend any time on building banked memory solutions for a new product.
The situation would be completely different if you already had invested a lot in an existing product and need a quick solution to extend it past a hard limit.
Besides the extra chips to decode the memory addresses, the software complexity will also increase.
By the way - why so much RAM? Are you going to run the application from RAM, or do you really have that much dynamic data to keep track of? It is quite common that much of the data are semi-static and can be moved to a large serial flash instead. A data logger that needs more bandwidth can be built with an external address counter, so the application (or external hardware) just writes out data a byte at a time, without thinking about the address. That would allow fast storage of many megabytes of high-speed-captured ADC data for example.
89c51 supports external 64k only by using one port pin I will interface another 64K
Thanks for giving information bye