topic Re: ADC Power control - M5223X / M5213 in ColdFire/68K Microcontrollers and Processors

ADC Power control - M5223X / M5213

mjbcswitzerland — Sun, 13 Apr 2008 10:13:36 GMT

Hi All

I have a few questions about the ADC in these devices in relation to its power modes.

According to the users' manual there are 5 different modes.
These operate partly by using the relaxation oscillator [OCO] (needs to be 8MHz). In addition there is a note about the ADC's clock being disabled if ADC is not equal to '1' in the SIM_PCE register.

However it seems as though there is no SIM_PCE register in these devices (SIM module).
Also, apart from in the ADC chapter, there is no reference to a releaxation oscillator in the devices or how it could be configured.

In order to complete a driver interface to this module I would like to find out whether these power modes are possible or whether the description in the users' manual is possibly incorrect.

Best regards

Mark Butcher

http://www.uTasker.com

Re: ADC Power control - M5223X / M5213

DavidS — Thu, 17 Apr 2008 23:29:53 GMT

Hi Mark,

The MCF5213 family does have a relaxation (dumb name) OSC on-chip. Better put, the MCF5213 has an on-chip OSC that can run at 8MHz and be used as an input to the PLL. This I’ve done in the past so it works fine.

The MCF5222x (K2U) also has this (or at least the documentation does). Haven’t tested ever.

The MCF5223x (K2E) does not have relaxation OSC.

I’m sure the reference to SIM_PCE in Section 28.5.8.1 should be changed to reference the PPMR (Peripheral Power Management) setting for ADC.

Regards, David

Re: ADC Power control - M5223X / M5213

mjbcswitzerland — Fri, 18 Apr 2008 01:08:27 GMT

Hi David

Thanks. This corresponds with latest information so all seems clear now.

Regards

Mark