i.MXRT1052 address pins connection for 16-bit Parallel NOR Flash

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i.MXRT1052 address pins connection for 16-bit Parallel NOR Flash

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mike4
Contributor III

Thanks Yuri,

I am glad we should be able to address the 256Mb Flash. We just want to make sure of the connections.

Our previous processor LPC3240 stated the following:

When using a system that implements 16-bit static memory, address signals A[23:1] are right-justified by one bit and output

on the physical address pins A[22:0]. Address signal A0 is not necessary because all transactions occur on half-word

boundaries. Address pin A23 is not used because the address space available for each CSn is 16 MB. This is done

automatically by hardware in the EMC controller when the value of MW is set to 0x1.

Therefore A23 was not valid and we connected A[22:0] to A[23:A1] on the flash (it has no A0 pin).  We created our own A23 by using a second chip select line and connecting it through gated logic to A[24] on the flash.

Is A23 valid when addressing a 16 bit wide parallel NOR flash with the iMXRT1052? Can we use the following design or do we need to gate an additional chip select like SEMC_CSX[0] to pin A24?

SEMC_DA0 – A1

SEMC_DA1 – A2

SEMC_DA2 – A3

.

.

.

SEMC_DA14 – A15

SEMC_DA15 – A16

SEMC_ADDR0 – A17

SEMC_ADDR1 – A18

.

.

.

SEMC_ADDR6 – A23

SEMC_ADDR7 – A24 ??

 

SEMC_ADDR8 – CS5

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539 次查看
mike4
Contributor III

Thanks again Yuri.  Just to make sure we understand (because booting off the flash is the most important part of the design)  the SEMC does not support address shifting mode like the other NXP MCUs that we have used in the past.  Therefore, A0 is valid but we do not use it. We start with A1 connected to A1 on the Flash (which does not have an A0 pin) and end with SEMC_CSX[0] - connected to A24.  This will then address a 256Mb address range.

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540 次查看
mike4
Contributor III

Thanks again Yuri.  Just to make sure we understand (because booting off the flash is the most important part of the design)  the SEMC does not support address shifting mode like the other NXP MCUs that we have used in the past.  Therefore, A0 is valid but we do not use it. We start with A1 connected to A1 on the Flash (which does not have an A0 pin) and end with SEMC_CSX[0] - connected to A24.  This will then address a 256Mb address range.

539 次查看
Yuri
NXP Employee
NXP Employee

Correct.

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539 次查看
Yuri
NXP Employee
NXP Employee

Hello,

 

The following is correct connection scheme for 16-bit parallel NOR flash:


SEMC_DA0 – A0  (really not connected)

SEMC_DA1 – A1 

SEMC_DA2 – A2 

... 

SEMC_DA14 – A14 

SEMC_DA15 – A15 

SEMC_ADDR0 – A16 

SEMC_ADDR1 – A17 

... 

SEMC_ADDR6 – A22 

SEMC_ADDR7 – A23 

SEMC_ADDR8 – CS5

SEMC_CSX[0] - A24

 

Have a great day,

Yuri

 

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