EzPort timing before configuration has been loaded.

[jun_chen]

I am trying to program MCF5213 via EzPort, and I found there is a  EzPORT initialization flow as below:

EzPORT initialization:
• EzPORT initialization obey Figure 2.
• Execute the RDSR command and continue only if the FS flag is cleared, this means the internal
flash is not secured.
• Execute WREN command
• Execute RDSR and see if WEN flag is set
• Execute WRCR command sending clock configuration
• Execute RDSR command and wait until the write in progress (WIP) flag is cleared.
• Execute RDSR command and check the configuration register loaded (CRL) flag is set. Verify
CRL is the only flag set (no WEP), otherwise there is an error.

My question is, how much frequency is propriety for Master to send instruction into Slave via EzPort before I set configuration register ?

[miduo]

See below application note on the Ezport programming:

https://www.nxp.com/docs/en/application-note/AN3897.pdf 

[TomE · Accepted solution]

The Data Sheet gives the characteristics in "2.5 EzPort Electrical Specifications". The maximum clock rate is Fsys/2. So it depends on what the default power-on frequency of Fsys is for your hardware.

The Reference Manual Section "16.3.2.1 EZPCK - ExPort Clock" says the same thing, Fsys/2. Except when reading data, and then the maximum is Fsys/8.

I'd start off really slow and see how fast you can get it before it stops working, but only after you get it working on a slow clock first.

Tom