Using FSMC bank1 and bank2 simultaneously

[troy1818]

Posted on July 18, 2013 at 00:01

Hi,

I use:stm32f4 (LQFP100)I want to:1. Use FSMC bank1 to control LCD2. Use FSMC bank2 to control NAND memory3. Use chip select to control active chipProblem:Chip select for bank1 (NE1) and chip select for bank2 (NCE2) is both placed on pin PD7.Question:Anyone know if it is possible to use bank1 and bank2 somehow, perhaps use GPIO to control the chip select signals on the two chip?According to manual:2. For the LQFP100 and BGA100 packages, only FSMC Bank1 and Bank2 are available. Bank1 can only support a multiplexed NOR/PSRAM memory using the NE1 Chip Select. Bank2 can only support a 16- or 8-bit NAND Flash memory using the NCE2 Chip Select. The interrupt line cannot be used since Port G is not available in this package.Regards,Rygel #fsmc

[Tesla DeLorean]

Posted on July 18, 2013 at 01:03

Rev 4 of the 405/407 Data Manual say OR not AND

For the LQFP100 and WLCSP90 packages, only FSMC Bank1 or Bank2 are available You could perhaps use a higher order address bit as a CS for a NAND device, as it's accessed more like a hard drive than a linear memory.

[troy1818]

Posted on July 18, 2013 at 12:14

Thanks a lot for the answer Clive!

According to my NAND memory (H27UBG8T2BTR-BC), minimum tCS (CS setup time) is 20ns. But my stm32f4 mcu has a tv(Data_NE) of 13 ns at 168Mhz (see below).tv(Data_NE) FSMC_NEx low to Data valid  -> tHCLK (~6ns) + 7 ns = 13 nsSo I think the idea was good but it will unfortunately not work in my case.I only have one executing thread in my SW so perhaps 2 GPIO pins are better choice as CE# to my NAND and LCD devices?Regards, Rygel

[troy1818]

Posted on July 21, 2013 at 03:22

Humm, perhaps does not matter how my SW looks, since FSMC is a HW thing.

I think controlling CS by address lines is my only option.Regards,Rygel