DM8148 GPMC

Aska

Intellectual 740 points

Hi,

If use GPMC_Wait[0] and GPMC_CS[0] for NOR Flash ,other use GPMC_Wait[1] and GPMC_CS[1] for NAND Flash.

May I ask the

Q1.DSP how to know the Wait [0] & CS [0] connection NOR Flash, wait [1] & CS [1] to connect NAND Flash?

Q2.If the Wait [0] & CS [1] is connected to the NOR Flash or the Wait [1] & CS [0] is connected to the NAND Flash,

whether there will be a problem? DSP How do know?

over 12 years ago

0 Biser Gatchev-XID over 12 years ago

TI__Guru**** 393215 points

Hi Aska,

Q1. The processor will not "know" what is connected on the GPMC bus. The NOR and NAND drivers should be written in such way, as to take care of proper GPMC configuration before access to the memory.

Q2. Again, software configuration.

0 Aska over 12 years ago in reply to Biser Gatchev-XID

Intellectual 740 points

Hi Biser,

Thanks for reply.

Could you tell me the software configuration have any reference document? thanks.

0 Biser Gatchev-XID over 12 years ago in reply to Aska

TI__Guru**** 393215 points

Hi Aska,

You should look at the NAND/NOR drivers provided with the Linux packages. There are also wiki pages, starting from this one: http://processors.wiki.ti.com/index.php/DM814x_AM387x_PSP_User_Guide

0 Aska over 12 years ago in reply to Biser Gatchev-XID

Intellectual 740 points

Hi Biser,

Thanks you provide information.but i have other question,please help to confirm.

Question:.SLC NAND Flash is supported on our PSP NAND driver . And default BCH8 ECC is used.

I saw the this link=>http://processors.wiki.ti.com/index.php/Managed_NAND

because SLC devices are costlier than MLC devices.So consider the use of e-MMC.

If use the e-MMC(16GB) for data storage Is there any question? have any document can reference it?

Could you idea or suggest?Thank you.

0 Biser Gatchev-XID over 12 years ago in reply to Aska

TI__Guru**** 393215 points

Hi Aska,

There are quite a lot of posts on this forum for eMMC usage. Try a search for "emmc" in the forum. I don't think there will be any issues. eMMC is connected to a processor MMC peripheral and it behaves like an MMC card.

0 Aska over 12 years ago in reply to Biser Gatchev-XID

Intellectual 740 points

Hi Biser,

The eMMC circuit connection is equivalent to the MMC it?

Whether other the eMMC reference documents?Thank you

0 Biser Gatchev-XID over 12 years ago in reply to Aska

TI__Guru**** 393215 points

Yes, except that there are 8 data bits and external pull-up resistors are usually not placed. Also please check whether the eMMC you intend to use supports 3.3V I/O supply (most of them do).

0 Aska over 12 years ago in reply to Biser Gatchev-XID

Intellectual 740 points

Hi Biser,

Could you help to check the below table.

The eMMC have RST_n signal ，how to connect this signal? thanks.

DSP signals	Dir.	eMMC signals	Dir.
MMC1_CLK	O	Serial resistance(22Ω) on CLK	I
MMC1_CMD	I/O	Connect to CMD signal and pull-up 10KΩ	I/O
MMC1_DATA0~MMC_DATA7	I/O	Connect to DAT0~DAT7 signal and pull-up 50KΩ	I/O

0 Biser Gatchev-XID over 12 years ago in reply to Aska

TI__Guru**** 393215 points

Hi Aska,

The signals in your table are correct. You may be able to skip the pull-ups on CMD and DAT0...DAT7 lines if you use the processor internal pull-ups. The RSTn signal can be connected to the processor RSTOUTn signal. You should watch out for voltage levels on this and all other signals - they should be the same on processor side and eMMC side.

0 Aska over 12 years ago in reply to Biser Gatchev-XID

Intellectual 740 points

Hi Biser,

Could you help to confirm the processor internal pull-up resistor value? thanks.

0 Biser Gatchev-XID over 12 years ago in reply to Aska

TI__Guru**** 393215 points

Hi Aska,

These figures can be found in DM814X Datasheet, Section 6.3, Parameter I_I. The typical input current with internal pullup/pulldown enabled is ±100uA, which would give a typical pull value of 33kOhm @ 3.3V I/O voltage or 18kOhm @ 1.8V I/O voltage. Please note that these are not real resistors, but equivalent electric circuits inside the processor, that's why their value is different for different I/O voltages.

0 Aska over 12 years ago in reply to Biser Gatchev-XID

Intellectual 740 points

Hi Biser,

Thanks for reply.

Now, there is still a confusing issue,do you know how can set mmc0 clock register to 48MHz?

Due to the document SPRS647C, Table 8-86 in page 336 write the fop (CLK) = 48MHz and see the documents "SPRUGZ8C," page 455 Figure 2-8 to point out

MMC_CLK from sysclk8 = 192MHz ,so could you help to reply?thanks.

0 Biser Gatchev-XID over 12 years ago in reply to Aska

TI__Guru**** 393215 points

No Aska, I work only on hardware forum questions, sorry.

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DM8148 GPMC