MCF52213 RSTO stays low

[gaminn]

Hello,

I have newly bought (never programmed) MCF52213 and when I turn VDD on, RSTO pin stays low all the time. No other pins are connected, only VDD and VSS. There are two 4.7 uF capacitors between VDD and VSS and 32 kHz crystal (and 18 pf caps and 1 Mohm resistor) on my evaluation board. I tried it with 2 pieces of MCF52213 - it is the same.

RSTO pin is not short-circuited to VSS or any other pin. RSTI pin is high. Supply voltage is 3.3V, rising edge of VDD lasts 17 us.

Here is an image of turning MCF52213 on. You can see, that there is peak on RSTO like the MCU tries to rise up RSTO.

.

Hope somebody can give me a suggestion.

Thank you

Martin

[gaminn]

Dear pgo,

really thank you for your help. Now everything is ok. I am a newbie to CF V2 - I didn"t know I have to set several pins (EZPCS, TEST, CLKMOD, XTAL) low or high. It"s not like HCS08 or CF V1 where you connect VDD and VSS and it runs. Thank you very much.

Martin

[pgo · Accepted solution]

Dear Martin,

Looking at the datasheet for the chip it would appear that a 32kHz crystal is not supported (1-48MHz only - I think - this detail hard to find!)

There is also some requirements for CLKMOD0/1 and resistors on XTAL - The details depend on the package being used.

For reference I've attached the schematic for a minimal circuit I have used.  Note- this circuit uses a fundamental-mode 48MHz crystal which tends to be scarce.  Most are 2nd overtone and unsuitable.  I forget if a lower frequency crystal can be used with the USB functionality.

bye