topic Re: MCF5272 QSPI Chip Selects in ColdFire/68K Microcontrollers and Processors

MCF5272 QSPI Chip Selects

cdavison — Wed, 03 May 2006 02:00:09 GMT

The naming convention for the 5272 QSPI chip selects seems to imply that they are active high, but the note under Figure 14-4 on page 14-11 of the User's Manual says that "Chip selects are active low". Are the QSPI chip select pins active high or active low?

Re: MCF5272 QSPI Chip Selects

mpeters — Thu, 04 May 2006 04:23:41 GMT

The QSPI Chip Select inactive level is programmable...it can be either active high or active low. This is configured with the CSIV bit (bit 12) of the QWR Register. Please refer to section 14.5.3 of the user's manual for additional information.

-mp

Re: MCF5272 QSPI Chip Selects

cdavison — Thu, 04 May 2006 04:33:38 GMT

If I read the data book right, the inactive level applies to all QSPI chip selects, so all chip selects are active high or all are active low; you can't have one active high chip select and the rest active low. Is this right?

Re: MCF5272 QSPI Chip Selects

mpeters — Thu, 04 May 2006 05:09:08 GMT

Yes, this is correct. They are not individually selectable. Either all chip selects are active high, or they are all active low.

-mp

Message Edited by mpeters on 05-03-2006 05:09 PM