Is SDRAM necessary that STM32F429 support TFT LCD?

[ray]

Posted on November 02, 2014 at 13:52

STM32F429V has 100 pins and support RGB565. In order to support TFT LCD, more memory is needed. Does it need to add external SDRAM? 429 has 256k internal RAM. Is it enough to support TFT?

Actually, the application UI is small and only 7 pages. Can I not add SDRAM in the schematic? 

#!rocketscience

[Tesla DeLorean]

Posted on November 02, 2014 at 14:26

The amount of memory will depend on the resolution, now wouldn't it?

[ray]

Posted on November 02, 2014 at 14:44

The resolution is 800x480. Do you know how to calculate the amount of memory?

Thanks.

[Tesla DeLorean]

Posted on November 02, 2014 at 15:22

The resolution is 800x480. Do you know how to calculate the amount of memory?

 

Ok, some some basic math here

16-bit colour depth, 2 bytes per pixel

2 x 800 x 480 = 768000 bytes

The 256 KB is broken into 192KB and 64KB (CCM). The CCM can't support DMA

[ray]

Posted on November 03, 2014 at 05:42

Thanks Clive. You are so nice.

[Johanan1]

Posted on November 03, 2014 at 09:15

The stm32F429 discovery board has a suitable SDRAM for this.

Look at the discovery board drawing.

This was my first prototype...

Johanan

________________

Attachments :

2014-07-27_16.56.49.jpg : https://st--c.eu10.content.force.com/sfc/dist/version/download/?oid=00Db0000000YtG6&ids=0680X000006I17K&d=%2Fa%2F0X0000000bia%2FuhdDLcUqj2M9mcYw2qwpvVzJ_uTzUPmDiBy2nqzNwhU&asPdf=false

[Tesla DeLorean]

Posted on November 03, 2014 at 17:52

The stm32F429 discovery board has a suitable SDRAM for this.

I think he's tried that, and looking to achieve some conflicting requirements in a low pin count device.

Generally trying to achieve small size and high functionality tends to require more exotic parts and board techniques, and these tend to drive the costs higher.

[Tesla DeLorean]

Posted on November 03, 2014 at 17:55

Thanks Clive. You are so nice.

Sorry for the tone, it gets frustrating at times.