Can address pin A25 (STM32F765II) be used for LCD 8080 interface in case of 16 bit data?

Forum|Forum|6 years ago
November 24, 2019
7 replies
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I am trying create drivers for LCD using 8080 interface and STM32F765II cpu. In order to config the cpu I use STM32CuBeMX and I can select line A25 to switch command/data even when I set 16 bits data bus. But also I found next text in the datasheet:

"In case of a 16-bit external memory width, the FMC will internally use HADDR[25:1] to generate the

address for external memory FMC_A[24:0]. In case of a 32-bit memory width, the FMC will internally use

HADDR[25:2] to generate the external address"

So my questions are:

Can A25 address line be used to switch command/data in case of 16 bit width? If yes how I can switch its state?

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Tesla DeLorean

Guru

You could use any of the external address bits.

You'd read/write to a different address, ie 0x60000000 or 0x60000000 + (1 << 25)

1 << 26 -> 0x40000000 which would be another bank select.

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YuoraAuthor

Associate

Thank you for answer.

it seems that when I use address 0x60000000 + (1 << 25) to read or write 16 bit width data it doesn't affect A25 pin but A24 pin is changed. It works like datasheet describes: "In case of a 16-bit external memory width, the FMC will internally use HADDR[25:1] to generate the

address for external memory FMC_A[24:0]". But stm32cubemx app allows select A25 pin to use for data/command switching in case of 16 bit width.

Is there any another way to set value to A25 pin? Or is it a bug in stm32cubemx application?