All:
From the TODA-00311 "Miniaturized Pulse Oximeter Reference Design," it appears that the minimum connections needed between the microcontroller and AFE device are the following:
SPI connections:
SPISTE
SPISIMO
SPISOMI
SCLK
Additional I/O:
AFE_PDN
ADC_RDY
RESET
DIAG_END
What is the minimum set of connections required?
4 SPI for sure + RESET
Can the other 3 I/O be handled via commands?
It looks like AFE_PDN may be a required I/O for power down.
It looks like ADC_RDY is not available as (status) register value, thus it also is required. Would it make sense to be able to poll for ADC_RDY if it were available, thus saving an I/O?
Also, it looks like DIAG_END is not available as (status) register value, thus it is also required. Again, would it make sense to be able to poll for DIAG_END if it were available, thus saving an I/O?
On the AFE4490, there are two additional I/Os - LED_ALM and PD_ALM. It looks like these are also available as (status) register values, so in an application that would use the AFE4490, would it be necessary to also include these as I/O's to the microcontroller?
