CPLD access EPPROM

C

c828

New Member

• Dec 1, 2006

• #21

I have been read your post and i want to thank you a lot. but i want to fed data to col and scan row. Ex:
*Data from EEPROM: A(1)="0011001100", A(2)="00001111"....
* I don't move all to led matrix, i want to take one bit of byte, it means: i take bit0 of byte 1, bit0 of byte2, bit0 of byte3...fed to 6b595. when bit0 of last byte to 6B595, i allow data at output of 6B595. Then i take bit0 of bye1, bit2 of byte2, bit2 of byte3....so on..
Your block is good but it can't do this???
Can you explain me again?
I'm vietnamse and i'm bad in English!
Thanks a lot!

 

K

kamdy

New Member

• Dec 2, 2006

• #22

I thonk if you change the way you are storing the data in the EPROM you will get the same result.Also you can do it by just changing the select bits of the multiplexer with the first 3 address line of the EPROM.

 

C

c828

New Member

• Dec 4, 2006

• #23

yes, I take d(6),d(7) and d(8) of counter14 fed to input of mux8-1. is it right? If it is right. i can take first 128 byte in eeprom. And when i display them on matrix led, i can scan them several times. But if I want to shift picture on matrix led, ex: shift left, what will i do?

 

K

kamdy

New Member

• Dec 4, 2006

• #24

You have to sore shifted patterns of data in the EPOM so when you display them the they appear as moving message

 

C

c828

New Member

• Dec 7, 2006

• #25

But I take data from PC (using Mscomm on VB), AT89S52 receives data from PC, then fed to RAM (EEPROM). So i think can't do that you said?

 

K

kamdy

New Member

• Dec 7, 2006

• #26

could you please send me the block diagram of your display so i could suggest a better solution

 

C

c828

New Member

• Dec 11, 2006

• #27

Yes, i post for you a my block diagram. On PC i can type any character and them display on led matrix. I fed data to colum and scan row because there are very lot of colum.
On PC, i can type any characters and display them on led matrix. Control bus controls CPLD take data from RAM62256 when 89S52 transmit the last data.

 

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• Doc1.doc

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C

c828

New Member

• Dec 14, 2006

• #28

I have post for you my block diagram. Can You help me?

 

K

kamdy

New Member

• Dec 15, 2006

• #29

I'm sorry I was not able to view it .Please post the block diagram in JPG fromat

 

C

c828

New Member

• Jan 2, 2007

• #30

Block

I'm sorry, i'm very busy and i'm late. Now i post my block, Can you help me?
Thank you very much!

 

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• block.jpg

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K

kamdy

New Member

• Jan 3, 2007

• #31

I have studied you block diagram and i Think that there is no need for the CPLD and the RAM. The function of CPLD and the RAM must me implemented by software routines in the 89C52 microcontroller . the attached figure shows a more simple moving message display. In this block diagram a serial EEPROM (24C512) is used to store the messages data send by the PC. The microcontroller reads the data from the serial EEPROM and convert it to serial then shifting it to the shift registers with row select data as shown in the block diagram

 

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• msg display.JPG

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C

c828

New Member

• Jan 4, 2007

• #32

yes, I can do that in 89S52 but i'm studing for my subject (CPLD). And I used RAM 62256 (paralell). I have to do that in CPLD. I want your help.
Thank you very much!

 

C

creeps

New Member

• Jan 9, 2007

• #33

i friends
i wane a vhdl program for universal shift register
if any one can plz provide it ofr me...

thanq.....