topic Re: MCF5475 - code execution from flash in ColdFire/68K Microcontrollers and Processors

MCF5475 - code execution from flash

Jaimy — Tue, 05 Feb 2008 18:28:55 GMT

Hi,

I am able to debug from flash, but i am not able to run the code stand alone. Do i have to change any settings to run the code directly from flash on reset. I am using Intel P33 flash. Using FB_CS0 for flash. Address range for flash is from 0xee000000 to 0xefffffff. Could someone help me out.

Jaimy

Re: MCF5475 - code execution from flash

w_wegner — Wed, 06 Feb 2008 20:05:18 GMT

Hi,

I am not sure if this applies to MCF547x/8x, too, but some questions:
- do you use BDM for debugging? If so, do you have a pullup on BKPT on your processor board? It is needed at least for MCF5373, although I did not find a reference in the data sheet
- also, on my MCF5373 board, i needed a pullup resistor on my console serial port RX line for U-Boot - I am not sure if this is a driver or hardware thing, but for my design U-Boot would not start up without this pullup or a level converter attached.

(The same might apply to /TA, if this signal is present on MCF547x, too)

HTH,
Wolfgang

Re: MCF5475 - code execution from flash

Jaimy — Thu, 07 Feb 2008 12:50:59 GMT

Hi,

BKPT is used and is pulled high. I have given serial port lines to rs232 level converter. /TA line is also used in BDM and is pulled high.

But one doubt is /TA line is also connected to WAIT of flash. But WAIT is only used in synchronous mode. On reset only asynchronous read mode is used. While debugging in initialisation file, /TA line is made GPIO. Only then i am able to access flash. But this is not possible in stand alone. On reset /TA is not GPIO.

Even when i am shorting /TA high, flash is accessible in debug mode without making it GPIO but not in stand alone. There is no way to disconnect WAIT from /TA in board. Attaching the interface diagram i have used. R/W, CLK, WP#, CS#, OE# , /TA are all pulled high.

Is it possible to use same flash for asynchronous as well as synchronous mode with one set of connections?

jaimy

Re: MCF5475 - code execution from flash

w_wegner — Thu, 07 Feb 2008 16:58:00 GMT

Hi,

sorry, I am neither an expert for MCF547x nor Intel P33 - in my own board with MCF5373L and Intel P30 flash I finally left out the connection of WAIT to /TA because I did not find a way to use it properly.

I hope there are others who can give more detailed advice for this specific configuration.

Regards,
Wolfgang