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Fast Parallel Port (32bite wide) to interface external IC using STM32F7 or H7

embvis
Associate III
Posted on June 11, 2017 at 22:18

Hi,

How fast it is possible to drive external IC using Paraller Port (32bit wide, mixed PINs from various port) via DMA or other technics. I have connected also exteral SDRAM to MCU.

It is possible to achive about 40 - 50 MHz update freq ot entire port ?

Thank you in advance for all sugesstions.

#stm32f7 #32bit-parallel-port #freq #parallel-port #stm32h7
6 REPLIES 6
Posted on June 11, 2017 at 22:38

Use the FSMC/FMC to write to a 32-bit data bus, and have external latch catch the write cycle (as if it were a SRAM or NOR type device)

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Posted on June 12, 2017 at 01:41

Hi. I use fmc to sdram. I want to established communication from mcu to other ic independly from sdram lines. Data from sdram should be go the fastest way to parallrl port. 

Posted on June 12, 2017 at 01:59

The bus can interface to multiple devices. The GPIO banks are only 16-bit wide and the addresses are sufficiently far apart that you can't DMA a 32-bit word to a pair of them in consecutive transactions. The bus width to the video dac also isn't wide enough.

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Posted on June 19, 2017 at 12:00

Turvey.Clive.002 wrote:

Use the FSMC/FMC to write to a 32-bit data bus, and have external latch catch the write cycle (as if it were a SRAM or NOR type device)

I have nucleo 767zi, how I can do that? I don't have any external memory righ now.

Posted on June 19, 2017 at 14:29

You'll need to review the pin list, and see how much of the FSMC/FMC you can escape. A 32-bit write will go to consecutive addresses on an 8 or 16-bit data bus.

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Posted on June 19, 2017 at 23:17

So how I should configure cubemx if i have clear pin, nothing else connected to stm32f767 nucleo. I want check performance this configuration.

Thank you in advance.