RSTO stays low on M52259EVB

[yibbidy]

Hi All,

I cannot program the MCF52259 on my M52259EVB board through either the inbuilt PE USB debugger or by using a PE Multilink Universal, they lock up when "checking system clock".  I noticed that the Reset LED is on all of the time, it is driven by the RSTO pin.  When I push the reset button, a user LED connected to DTIN0 goes out, then back on again when the button is released.  I've checked the supply voltage and it is 3.3V.  According to the datasheet, the following affect the RSTO pin:   

• External Reset
• Watchdog Timer Reset
• Loss-of-Clock Reset
• Loss-of-Lock Reset
• Software Reset
• LVD Reset

I've checked RSTI as being high.

I've checked the XTAL clock input with a CRO and confirmed that it gets a 48MHz signal that is the same as on a working M52259DEMO board.  I have confirmed that CLKMOD0 (xtal or external clock) is high (xtal) and CLKMOD1 is high (PLL active).  I've tried CLKMOD1 low (no PLL), same result.

I've installed an external 8MHz oscillator module, confirmed the clock with a CRO on the EXTAL pin, set CLKMOD0 low, and tried CLKMOD1 both high and low, still RSTO is low.

I tried using the internal oscillator, by setting CLKMOD[1..0] low and pulling XTAL high, RSTO remains low.

RSTO goes only to the breakout header, BDM header, the LED, and an onboard CPLD.  It does not go to the onboard P&E BDM.  I cut the trace to the CPLD in case it was a fault there, just in case the CPU was not driving the pin low, though I didn’t think that would disrupt the CPU anyhow.

Does anyone have any ideas as to what the trouble could be or suggest what else to try?

Thanks,

Shaun

[yibbidy · Accepted solution]

I changed the PCF52259 over for a MCF52259 and it's all good now so I assume that the chip was dead.  I'm guessing PCF means pre-production or pre-qualified but otherwise the same.

Shaun

[TomE]

> Does anyone have any ideas as to what the trouble could be or suggest what else to try?

You're doing pretty well already.

I note it is an M52259EVB, and you have a working M52259DEMO board, so this is unlikely to be a design problem

Did this board EVER work? If it used to work, what did you do that made it stop working?

Search for "RSTO" on this forum and see if any previous posts are of any help.

Check the Debug Connector signals with a CRO in case something shows up there. Check your grounding between the stuff on the bench and the PC.

Does the same debug pod work on the M52259DEMO?

Use a different USB cable. Seriously, this matters sometimes.

Tom

[yibbidy]

Thanks Tom.

Even without a USB cable or BDM connected the RSTO line is always low.  Unfortuantely the M52259DEMO board has no facility for an external BDM, one is stuck with the onboard OSBSM.    I don't know the history of this board.  I bought it off eBay about a year or so ago, after Freescale discontinued it, it was supposed to be new and looked to be such, but I guess one never knows :smileyhappy:  I think I'll change the MCF52259 and see what happens. I appreciate your response as this is the first time I've gotten down to this level on this processor and your response gives me confidence that there is not something silly that I have overlooked.

Regards, Shaun