Microcontroller selection

[ajaychordiya]

Hello,
I am developing one application with high speed inputs and outputs.
Peripheral requirement for application are as below:
1. 4 PWM output with resolution 32bit and 2MHZ clock OR external clock source for PWM with 32bit resolution
2. 8 external interrupt pins. Dedicated interrupt request for each interrupt
3. One UART(for programming)
4. One I2C (100kHz)
5. Clock source : external crystal support, clock should be higher than 40MHz.
6. Pin count : 32 to 48
7. Flash : 32kB to 128kB

Is any microcontroller available with these features?

[xiangjun_rong]

Hi, Ajay,

As you know that the GPIO/Flash/IIC/UART modules are peripherals almost each processor has, I suggest you consider the processor which has eFlexPWM module, for example KV5x/KV4x, MC56F827xx/MC56F84xxx, if your application is auto, you can use MPC56xx.

Almost all PWM module are 16 bits registers instead of 32 bits register, but the actual PWM resolution is dependen on the ratio of driving PWM clock frequency and PWM output signal frequency. For example, if the PWM driving clock is 100MHz, the PWM output signal is 1MHz, the PWM resolution is only 6~7 bits. If the PWM output signal frequency is 10KHz, the PWM resolution is about 13~14 bits. For eFlexPWM module, it supports nano-edge PWM signal, in other words, it can increase actual 5 bits PWM resolution.

This is KV5x/KV4x website:

Kinetis V Series: Real-time Motor Control & Power Conversion MCUs based on ARM Cortex-M0+/M4/M7|NXP 

this is DSC website:

Digital Signal Processors/Controllers|NXP 

Hope it can help you

BR

XiangJun rong

[mjbcswitzerland]

Hi

Kinetis parts have either TPM or FlexTimer to generate PWM signals. Depending on the part chosen more that 10 such outputs can be generated.

However the PWM resolution is max. 16 bits (that is, in the best case [slower PWM frequencies], you will be able to get about 0.002% Pulse width resolution). When you specify 32 bit it would mean that you require 0.000000025% resolution which is not possible with this module.

There are several hundred devices available that fulfill the other requirements - in fact almost any Kinetis part that you look at will (apart from the very few sub-48MHz parts) and the high-end ones with large pin counts.

Regards

Mark