Prometheus CPU User Manual V1.44
Page 52
Prometheus A/D Operating Modes
The following control bits and values are referenced in the descriptions in the table below.
AINTE
Base + 4 bit 0
SCANEN
Base + 3 bit 2
FIFO threshold
Base + 5 bits 5-0
STS
Base + 3 bit 7
LOW, HIGH
4-bit channel nos. in Base + 2
ADCLK
Base + 4 bit 4
AINTE SCANEN
Operation
0
0
Single A/D conversions are triggered by write to B+0.
STS stays high during the A/D conversion.
No interrupt occurs.
The user program monitors STS and reads A/D data when it goes low.
0
1
A/D scans are triggered by write to B+0. All channels between LOW and HIGH will
be sampled.
STS stays high during the entire scan (multiple A/D conversions).
No interrupt occurs.
The user program monitors STS and reads all A/D values when it goes low.
1
0
Single A/D conversions are triggered by the source selected with ADCLK.
STS stays high during the A/D conversion.
A/D interrupt occurs when the FIFO reaches its programmed threshold.
The interrupt routine reads out a number of samples equal to the FIFO threshold
each time it runs.
1
1
A/D scans are triggered by the source selected with ADCLK.
STS stays high during the entire scan (multiple A/D conversions).
A/D interrupt occurs when the FIFO reaches its programmed threshold.
The interrupt routine reads out a number of samples equal to the FIFO threshold
each time it runs.
