I2C for comunicate a MC9S08QE32CLD with a MCP23017

[karguar]

I'm new in the Freescale Universe, and I have a practice with a MC9S08QE32CLD for comunicate with a MCP23017, I have a problem with the set up for the I2C communication process.

thanks for the collaboration

karguar

[Teckna]

Hi karguar,

MQX is not supported by HCS08 family sorry!

You can see in MC9S08QE32 reference manual at chapter 12 (IIC).

What is exactly your problem?

Regards!

[karguar]

I want to  work with a external clock 10 MHz, I think that it's the issue, because i don't know how configure the external clock.

thanks

[Teckna · Accepted solution]

Hi karguar,

i don't know MC9S08QE32 cpu but i have read only its RM. Have you read RM??:smileywink:

The clock used by I2C is ICSOUT as shown in screenshot:

In the clock block diagram you see that ICSOUT can be referred to the external clock source setting CLKS and BDIV.

To configure external clock for I2c you must have:

ICSC1 = 0b10000000;

ICSC2 = 0b00101010;

I hope it helps.

Regards!

[Teckna]

Please indicate your compiler and MQX version.

[karguar]

sorry but I don't understand what is the mean of MQX, I'm using codewarrior 10

thanks