Hello friends,
Im using 7 inches TFT module (800x480) with LPC1788 controller. This is the first time I'm using a TFT module. Somehow I have managed to get some theoretical idea about TFT. But I have confused with the use SDRAM with TFT module. Is SDRAM is optional or it is compulsory if we are using a TFT LCD especially 7 inches LCD? Can someone please help me regarding this issue?
With SDRAM you typically have to configure both the Controller, and the Memory Device with parameters related to speed, geometry, and refresh, I tend to use "programming" to achieve that. A lot of externally interfaced devices/buses need configuring on current generation micro-controllers.
With LCD panels your likely to have to program in timing, framing, and geometry too, and set up DMA type transactions.
Thank you very much Westonsupermare Pier for your kind reply. Now I started to configure SDRAM in LPC1788 controller. But I couldn't find a formula to fing a value for DynamicRefresh Register. Can someone please help regarding this. Thank you.
That would depend on the refresh period of the SDRAM you have chosen, but not mentioned. This would perhaps be 8 or 16 ms, and the controller would likely need this period expressed in it's clock cycles?
But I couldn't find a formula to fing a value for DynamicRefresh Register For that you will have to read the datasheet of the SDRAM that you are using _very carefully_ and also refer to the timing diagrams that are given in the datasheet. The values may not be given to you directly as is in the datasheets. you will have to study the datasheet and figure them out. Depending upon the memory organization, the timings are to be configured. The timings are nearly same for the SDRAMs with same memory organization (even though the manufacturers may be different).
Thank you for all for your kind reply. I configured the SDRAM with LPC1788. Now I want to write and read data from SDRAM. I can find the procedure in the SDRAM datasheet for write and read operations. But I cannot find any buffers for that operations in the LPC1788 datasheet. Say for example if I want to set the mode register how do I transfer the value to the EMC address pins. Or can i use the GPIO registers for this purpose. Kindly someone guide me on this issue.....