Looking for programmable device (FPGA, CPLD...???)

May 02, 2007 5 Replies
M

Hi,



I want to build a board to connect a microcontroller to a TFT display. The board consists of the microcontroller, a programmable device and a FPC connector for the screen. Since I want to test different screens, and each of these has a different pinout and line number for the FPC cable, the programmable device is needed to reroute the lines from the microcontroller and the power supply lines. Basically, it should consist of a latch block to hold the address lines, bidirectional data lines and control/status lines, and power supply including ground. The output current for the supply is maximun 50mA, and the switching frequency at about 5Mhz.



The FPC connector will be soldered according to the cable size, since the board will have a large array of connection pads to accomodate this part.



I've never try a FPGA neither a CPLD so that's new field for me, but I think that is the type of component that I should use to interface the microcontroller with the screens. Any comments will be highly appreciated.



Mark.



Vote
Twitter Facebook LinkedIn
A

An FPGA would be overkill if your design only required a small percentage of the chip's resources. It sounds like a CPLD would be more than adequate for the job, and would have the advantage of retaining its configuration when power is removed, although, if you used an FPGA, and you loaded the configuration data from the microcontroller, you could possibly avoid the hassle of needing a boot PROM. You can download the vendor's development software (Altera Quartus or Xilinx ISE) and try compiling a prototype project before making a final decision. Use Verilog.

Vote
Twitter Facebook LinkedIn
M

When using one of this programmable devices, is it posible to transmit a voltage level (5V or 3.3V) from one input to an output, so I can reroute the Power Supply lines.?

Mark

Vote
Twitter Facebook LinkedIn
A

No. PLD outputs are standard logic outputs with limited current drive capability. I suppose you could take a few hundred microamps or even a milliamp or two; but it would be bad practice. You can't route different voltages. Outputs belong to a particular I/O bank which has power supplied from a dedicated VDD pin or pins.

Vote
Twitter Facebook LinkedIn
J

No.

JosephKK Gegen dummheit kampfen die Gotter Selbst, vergebens.   --Schiller
Vote
Twitter Facebook LinkedIn

Join the Discussion

Have something to add? Share your thoughts — no account required.

Didn't find your answer?

Ask the community — no account required