PIC18F85J90 and cypress 62167

[bourne]

Hi everyone,

I am trying to write and read inside a memory cypress 62167 with a PIC18F85J90. Here is my programs for read and write in the memory and the port configurations, i precise that the I/O are on the port D, the adress bits are on the ports G, H and J (21 bits) and on the port C (C1 and C0) :

[temtronic]

a few of points....

1) since your program is just 'snippets' , we don't know if you're controlling the I/O pins with 'fast_io()' or letting the compiler handle it.

2) what port/pin is LED2 ?

3) 50us between write then read may be too fast,though I don't have the specs on the Cypress part.

4)use of 'random' data is bad in testing any program.

5) always add 'errors' to the use RS232(...options...).

6) if possible, add code to send the data 'written to Cypress', and 'read from Cypress' to a PC terminal program.

7) slow down the overall 'loop' to say 1 or 2 Hz for debugging purposes.

8) what 'clock' speed?

most of these deal with 'timing' issues which means reading the Cypress datasheet and confirming you're not going faster than allowed.

hth
jay

[bourne]

Hello,
Thank for your response

1) I do not use fast I/O, I have just took off the part interupt for the serial ports and how I fill the random table (which is not important for my problem).

2) LED2 is ont the pin 2 of the port B.

3) I saw in the datasheet that the times necessary for the memory and less than 50 ns so I put a time which is bigger than necessary.

4) The random table is a table that I fill myself with a special algorithm, I know what is inside (random is only a name for that table).

5) I add it in my program thanks.

8) Clock speed is the frequency that I am working at...I forgot the #fuses that i used, I add it now.

[bourne]

[dyeatman]

The datasheet I am reading says the Read AND Write cycle times
are either 55 or 70ns MINIMUM depending on the two digits at the end
of the part number so 50ns is too fast.

Without using FAST_IO the Set Port function is useless.
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[bourne]

Hello,

I write those #use FAST IO:
#use FAST_IO(D)
#use FAST_IO(G)
#use FAST_IO(H)
#use FAST_IO(J)

I did not know if it was necessary for the address ports so I tried with and without, I have no changed, the LED is blinking even if it should not...

My functions write and read are they correct? I wonder if there isn't an error, but I cannot find where...

Thanks

[Ttelmah]

It's not 'necessary to address ports'. It makes it your job to set TRIS correctly. Without these, the compiler takes over controlling the TRIS, and will do it automatically based upon the operations you perform on the port. Makes touching TRIS yourself pointless and unnecessary. For 99% of users, unless they want the ultimate speed or are doing something like outputting a few bits at once on a port they want to otherwise remain as input, it is safer, and simpler to just ignore TRIS completely, and let the compiler handle it.
The point is that without the fast_io lines, these lines:

set_tris_a(0xBC); //CLKI in input et CLKO in output
set_tris_h(0x00); //port h, g et j in output
set_tris_g(0b00000);
set_tris_j(0x00);
set_tris_c(0x80); //port C in input pour RX,

Basically won't work, since the compiler _will_ override them itself.

[bourne]

Thank you, I took off the address port part.

the fact is that it still does not work...

Do you think my write/read functions are correct?

Thanks

[temtronic]

some things....
what voltage is the PIC powered by ?

though NOT an error,rather a programming style, you should rename your functions to write_cypress(), read_cypress(). Just 'read' and 'write' will be confusing later, especially if you add other devices.

play 'computer' and put a scope, DVM or LEDs on the I/O pins(remove the Cypress part) and see what is happening.'single step' through a write and a read 'cycle' and confirm the correct pins are being used.

hth
jay

[bourne]

thank you for your response Jay

I put 5V on the card, and then a regulator is powering the PIC, on that part everything is ok.

There is a big problem, when I write in the memory and then I try to read I do not have the same.
The problem is the following, I write a data to an adress, then I do the same to another adress.
When I try to read at the adress of the first data, I take back the last data written.
Here is the code:

[temtronic]

you need to show us your complete program not just 'bits' of it..

Also it would really help to define 'actions'. IE instead of 'output_h(0x01); something like cypress_high_address( 0x01); gives you and us a better idea what you're doing. Actually a small macro or function to create the address as it spans two ports is much better.

something like

write_cypress( address,data);
read_cypress(address,data);
where address is a 20bit number(int32) and data is an 8bit number(int8).

Also there are a LOT of 'chip enables' to this device.You should have them 'defined' and create a function that properly sets/resets them based on required action.

I don't have that device and cannot create the 'driver ' for you as I can't test it, that's why you need to show us your program.

Also ,most PICs will default peripherals like ADC to I/O pins. You need to disable them early in your code.

What is the real PIC and Cypress Vdd ?

hth
jay

[bourne]

problem solved, the memory had a problem

thanks to all of you for your help