Timed Samples

Timed sampling with Logic Scope

Timing setup

The ARM can sample the up to 32 data lines at 1 MHz rates in BASIC. The software library LogicScope.bas is used to coordinate this sampling. Other sample rates that are multiples of 40 uSec are also supported.

While sampling data the CPU is consumed gathering the 400 samples and then sending them to the PC, at which point processing of the user program can continue.

Example

#include <LogicScope.bas>         ' call in support for LogicScope functions
#include <HWPWM.bas>
'...

' user code to generate the stimulus -- the ScopeDemo engages the HWPWM

HWPWM (1,200,10)
HWPWM (2,200,20)
HWPWM (3,200,40)
HWPWM (4,200,80)
HWPWM (5,200,16)
HWPWM (6,200,32)
HWPWM (7,200,40)
HWPWM (8,200,45)

  ...

while 1
   call doLogicScope (50,0,0)      ' 50 uSec, and trigger on any state (mask =0, trigger =0)
   stop                                      ' stop needed only to handshake with the PC for continuous tracing
loop

keywords: Logic Scope