MOGlabs ARF021, Manual

Page: 61 / 134

7.7 Counters
51
Figure 7.5:
Example of pulse generation using the CHx-OFF input. Red is
TTL signal; blue is the RF signal.
7.7 Counters
Fast digital counters can be accessed for each digital input pin. XRF
devices can use these counters in advanced table mode (
§
9.4);
ARF
devices can only use them manually in scripts. To use a counter,
the associated pin must be in READ mode and the counter function
activated. The maximum edge-detection rate on the high-speed bus
is 50 MHz, and level-detection ( HIGH and LOW modes) accumulates
125 counts per microsecond.
The syntax to control counters is
EXTIO,COUNTER,ch,pin,command
,
where
command
is one of the following:
READ, V[ALUE]
Return the counter value as a 32-bit number
RESET, C[LEAR]
Reset the counter value to zero
E[NABLE]
Activate counter and begin accumulating count
D[ISABLE]
Deactivate counter but hold count value