TMS570LC: Flash on EMIF Byte Enables

Johannes Glienke

Hello,

I'm trying to connect an external 16MiByte asynchronous NOR-Flash to the EMIF-Interface of the TMS570LC. The technical reference manual shows an example interface for connecting a 8MiByte flash to the EMIF (SPNU563 page 826). In this example the byte enable lines are connected to the flash.

The flash chips I wanted to use has no ability to connect byte enables. E.g. http://www.farnell.com/datasheets/1674446.pdf

Is it possible to use a flash without byte enables inputs to the EMIF?

Kind regards,

Johannes

over 11 years ago

0 Zhaohong Zhang over 11 years ago

TI__Mastermind 22715 points

Johannes,

For 16 bit wide Flash, you need to hook EMIF address [0..] to Flash address [1..], and EMIF_BA0 to Flash address[0].

Thanks and regards,

Zhaohong

0 Zhaohong Zhang over 11 years ago in reply to Zhaohong Zhang

TI__Mastermind 22715 points

Johannes,

I would like to make a correction to my earlier post. The flash chip you referred to has a different naming convention. The lowest address pin 1s named as A1 instead of A0. You should correct the address pins as follows.

EMIF Address [0..20] <-> Flash address [2..22]

EMIF_BA[1] <-> Flash address [1]

Thanks and regards,

Zhaohong

0 Johannes Glienke over 11 years ago in reply to Zhaohong Zhang

Prodigy 40 points

Zhaohong,

thanks for your answer. You write how to connect the address registers from EMIF to Flash.

The reference manual says that you have to connect EMIF_nDQM[1:0] to the byte enable inputs of the Flash (BE[1:0]).

Isn't it necessary for connecting this type of flash?

Kind regards,

Johannes

0 Zhaohong Zhang over 11 years ago in reply to Johannes Glienke

TI__Mastermind 22715 points

Johannes,

Those signals are used for byte access. You do not have to hook up those signals if they are not supported by your Flash device.

Thanks and regards,

Zhaohong

0 Johannes Glienke over 11 years ago in reply to Zhaohong Zhang

Prodigy 40 points

Zhaohong,

where did you get this information from? I can't find this in the reference manual or the documentation of the flash device.

Kind regards,

Johannes

0 Zhaohong Zhang over 11 years ago in reply to Johannes Glienke

TI__Mastermind 22715 points

Johannes,

You need to first check what signals are need for your flash chip. If the flash chip does not need byte enable, you just just leave the unused EMIF signals open.

Thanks and regards,

Zhaohong

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TMS570LC: Flash on EMIF Byte Enables