i.MX Processorsのトピックi.MX25 Serial Boot Configuration

i.MX25 Serial Boot Configuration

LI_Dave — Thu, 18 Jul 2013 02:42:18 GMT

I'm trying to boot a blank i.MX25 using the UART boot mode and have a question about what external boot pins really matter in this case.

I of course have BOOT_MODE_0 and BOOT_MODE_1 pulled high to select UART/USB Boot. I've also got the three BT_UART_SRC lines pulled LOW to select UART1. It would appear that nearly all the other boot config pin states are irrelevant to UART boot, but I'm not so sure about the BT_LPB_FREQ pins which configure the Low Power Boot mode. Do they need to be set correctly (111) to ensure successful UART boot? Is there anything else that needs to be tied to force a UART 1 Boot?

Thanks,

Dave

Re: i.MX25 Serial Boot Configuration

Yuri — Thu, 18 Jul 2013 03:15:00 GMT

General approach is as following - It is recommended to provide (proper / reasonable) configuration for all boot pins,

do not leave some of them free.

Re: i.MX25 Serial Boot Configuration

LI_Dave — Fri, 19 Jul 2013 01:06:02 GMT

Yuri, thanks for the reply I understand that is what is recommended. Given the choice I would follow the PDK schematic. I have a board though that is NOT as recommended (not my design) and I'm trying to understand if it will properly serial boot or not.