MC9S08GT16 resistor/cap on reset line optional?

[Kerms]

Hello,

I am wondering if the RC filter on the reset line is optional on the MC9S08GT16. The reason I ask is that i built a board without them and when I hook it up to my programmer it won't connect.

I am using the DEMO9S08QG8's BDM port to program my board.

Any advice on maybe why its not able to connect?

-Aaron

Edit:

To be more specific I am getting the error "The target MCU is not responding. Please turn MCU power off...."

Here is the output windows:

Windows NT detected.
USB HCS08/HCS12 MULTILINK detected - Flash Version 5.72
Frequency change to ~0hz.
Frequency change to ~0hz.
USB HCS08/HCS12 MULTILINK detected - Flash Version 5.72
Frequency change to ~0hz.
Frequency change to ~0hz.
Frequency change to ~0hz.
Frequency change to ~0hz.
Frequency change to ~0hz.
Frequency change to ~0hz.
Frequency change to ~0hz.
Frequency change to ~0hz.
Frequency change to ~0hz.
Frequency change to ~0hz.

Error: Can not enter background mode .

Frequency change to ~0hz.
Frequency change to ~0hz.
USB HCS08/HCS12 MULTILINK detected - Flash Version 5.72
Device is 9S08GT16A.
Mode is In-Circuit Debug.
IO registers loaded for MC9S08GT16A from C:\Program Files\Freescale\CodeWarrior for Microcontrollers V6.1\prog\REG\MCU100F.REG
Error: The debugger is currently not able to run
due to loss of contact with hardware.
No Link To Target

in>

Maybe its because I have an external osc? I have a 32.768Mhz osc

Message Edited by Kerms on 2008-03-03 10:07 PM

[peg]

Hi Kerms,

The GB60/GT16 manual shows nothing on the reset pin in the recommended connections where the GT16A manual now shows an RC on both reset and IRQ but notes that they are only neede for EMC sensitive applications.
I have not found them necessary. Although I will soon be adding them as a belts and braces approach to increase EMC immunity.
If you are trying to connect to a blank part it will be running in SCM when you connect and whether or not you have crystal should be irrelevant.

[Kerms]

Thanks peg,

I am still not able to connect to my device so I am thinking I should try a simpler setup by removing the rest of the circuitry from my design.

Also does IRQ need to be connected? Mine is floating. 

Thank you,

Aaron

[Kerms]

Oops found my bug.

I had "Cyclone Pro  Power Control" setting's Provide Power to target checked.

I unchecked it and eveyrthing works now.

Although ... Did I mess up in placing a 32.768mhz crystal or is that ok?

oh and for clarification this is the GT16A

Message Edited by Kerms on 2008-03-04 08:30 PM

[peg]

Hi Kerms,

You don't NEED anything connected to IRQ.

You have only "messed up" by placing the 32k crystal if in fact you could have got away with using the internal clock source.
You may have a valid reason such as accuracy/stability for using an external crystal.