High Drive mode in FRDMKL25Z

Questions » High Drive mode in FRDMKL25Z

10 years, 10 months ago.

How to use high drive mode in FRDMKL25Z. The datasheet says that the register PTx_PCRn has to be configured to obtain the high drive capability. Please help me out with configuring the registers.

1 Answer

10 years, 10 months ago.

Dear Santosh-san,

I tried to find PORTx_PCRn in mbed source, but could not find one.
So, in the Reference Manual of KL25Z, 11.5 memory map and register definition
there is a list of address(es) of these ports.
For example if we use D4, which is PTD4 of KL25Z,
the register would be PORTD_PCR4 which is 4004_C010 according to the list.
The drive strength bit is DSE which is bit 6 of PORTx_PCRn, so it is 0x40

So if you say

#include "mbed.h" 

DigitalOut dout(PTD4) ; 

int main() {
uint32_t *PORTD_PCR4 = (uint32_t*)0x4004C010 ; 

 *PORTD_PCR4 &= ~0x40 ; /* low drive strength */ 
 *PORTD_PCR4 |= 0x40 ;  /* high drive strength */ 

/* do whatever you like to */ 
}

Please note that this is what I "think" work, but I have not tested it.

moto

Accepted Answer

All those registers are included in the CMSIS files, no need to define the address manually. Here is the relevant file: http://developer.mbed.org/users/mbed_official/code/mbed-src/file/e03396e14338/targets/cmsis/TARGET_Freescale/TARGET_KLXX/TARGET_KL25Z/MKL25Z4.h

From there it should be addressable as:

PORTD->PCR[4]

posted by Erik - 03 Feb 2015

Wow, that file is very helpful!
Then we can say

PORTD->PCR[4] |= PORT_PCR_DSE_MASK ;

moto

posted by Motoo Tanaka 03 Feb 2015

Correct :). They are defined by the manufacturer, so what they define exactly differs a bit (as you found out, Freescale also defines bit masks, not all have them), but in principle it makes it alot easier to use those.

posted by Erik - 04 Feb 2015

Thanks for the reply. It is working for me.

posted by Santosh Kulkarni 04 Feb 2015

Santosh Kulkarni

Important changes to forums and questions

10 years, 10 months ago.