ADC FIFO conversion speed

jason_zhang — Fri, 17 Jun 2016 08:26:41 GMT

Hi,

I am using the ADC FIFO mode to get 3 anolog channels results.

When continuous conversion and interrupt are enabled, the interval time is about 300uS that can jump to ADC Interrupt.

I want to change the interval time into 1mS by the below method:

1. ADC Interrupt enable per 1mS in the timer interrupt. // ADC_SC1 |= ADC_SC1_AIEN_MASK;

2. ADC Interrupt disable when get out of the adc interrupt. //// ADC_SC1 &= ~ADC_SC1_AIEN_MASK;

But the interval time is 3mS, could you kindly explain why the speed has been down.

MCU:MC9S08PA60

ADC setting: ADC FIFO mode/12-bit conversion/Long sample time/3-level FIFO is enabled

Thank you!

Jason

topic ADC FIFO conversion speed in 8-bit Microcontrollers