AM335X and GPIO1_20/GPIO3_18

michael musset

Hi,

We have cloned the Beaglebone black and we are using other pins .

I've a question on how I can guess the address of the GPIO1_20 ( R14 ) ? getting the address of pins used by the beaglebone black is easy. But I couldn't figure out how to do this for GPIO3_18 and GPIO1_20.

over 10 years ago

0 Biser Gatchev-XID over 10 years ago

TI__Guru**** 393215 points

Hi Michael,

What do you mean by address? If you need the address of the pinmux register for the pin you should check the AM335X TRM Rev. L section 9.3.1. Registers named conf_xxxxxxx are the pinmux registers. Pins are named after the pin function in mode 0.

Thus GPIO3_18 is on pin MCASP0_ACLKR (pinmux register conf_mcasp0_aclkr), resp. GPIO1_20 is on pin GPMC_A4 (pinmux register conf_gpmc_a4).

0 michael musset over 10 years ago in reply to Biser Gatchev-XID

Expert 1135 points

thx for the answer,

How did you find that GPIO3_18 is on MCASP0_ACLKR ?( I didn't find it in the document )

And I'm not sure that mode 7 is the GPIO :
0x1a0 0x07 /* GIO3_18=0*/
0x050 0x17 /* GIO1_20=1*/

0 Biser Gatchev-XID over 10 years ago in reply to michael musset

TI__Guru**** 393215 points

Check Table 4-1 in the AM335X Datasheet Rev. H. And yes, mode 7 is GPIO (same table).

0 michael musset over 9 years ago in reply to Biser Gatchev-XID

Expert 1135 points

Hi, I didn't find this table in the recent documentation of the processor :

http://www.ti.com/lit/ug/spruh73l/spruh73l.pdf

0 Biser Gatchev-XID over 9 years ago in reply to michael musset

TI__Guru**** 393215 points

You are quoting the TRM. I was talking about the Datasheet. The link on the product page is missing at the moment, I suppose a new datasheet will be available today or tomorrow. I'm attaching the last available version:

am335x DM_Rev.H.pdf

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AM335X and GPIO1_20/GPIO3_18