%11010 Smart-Pin scope mode trigger and arm values

JonTitus

The scope mode includes settings for a 6-bit arm and a 6-bit trigger value. That's a range from 0 to 63. How do these values relate to an analog-input signal that has an 8-bit resolution (0 to 255)? In an example program, these values get bitwise ANDed with $FC:

scp_x long (trigger_level & $FC)<<8 + (arm_level & $FC) + scope_filter   '  =  TTTTTT00AAAAAAFF

Perhaps the 2 LSBs of the arm and trigger values are internally set to %00 and the arm and trigger values then exist as multiples of four: 0, 4, 12, ... ... 252? --Jon

evanh

The 6 Most Significant bits of each. The relationship is in the main prop2 doc just under the Hann/Tukey filter shapes. There is also mention of the samples being "normalised" to 8 bits. They're only 5 or 6 bits effective anyway.

JonTitus

Thanks, EvanH.