SPC563M64L7 datasheet(31/48 Pages) STMICROELECTRONICS

31 / 48 page

SPC563Mxx

Device overview

Doc ID 13850 Rev 6

31/48

The eQADC prioritizes and transfers commands from six command conversion command

‘queues’ to the on-chip ADCs or to the external device. The block can also receive data from

the on-chip ADCs or from an off-chip external device into the six result queues, in parallel,

independently of the command queues. The six command queues are prioritized with

Queue_0 having the highest priority and Queue_5 the lowest. Queue_0 also has the added

ability to bypass all buffering and queuing and abort a currently running conversion on either

ADC and start a Queue_0 conversion. This means that Queue_0 will always have a

deterministic time from trigger to start of conversion, irrespective of what tasks the ADCs

were performing when the trigger occurred. The eQADC supports software and external

hardware triggers from other blocks to initiate transfers of commands from the queues to the

on-chip ADCs or to the external device. It also monitors the fullness of command queues

and result queues, and accordingly generates DMA or interrupt requests to control data

movement between the queues and the system memory, which is external to the eQADC.

The ADCs also support features designed to allow the direct connection of high impedance

acoustic sensors that might be used in a system for detecting engine knock. These features

include differential inputs; integrated variable gain amplifiers for increasing the dynamic

range; programmable pull-up and pull-down resistors for biasing and sensor diagnostics.

The eQADC also integrates a programmable decimation filter capable of taking in ADC

conversion results at a high rate, passing them through a hardware low pass filter, then

down-sampling the output of the filter and feeding the lower sample rate results to the result

FIFOs. This allows the ADCs to sample the sensor at a rate high enough to avoid aliasing of

out-of-band noise; while providing a reduced sample rate output to minimize the amount

DSP processing bandwidth required to fully process the digitized waveform.

SPC563M64L7 Datasheet(PDF) 31 Page - STMicroelectronics