Owner's manual

Chapter 3: Architecture
38
The digital I/O lines are capable of sinking up to 32mA at logic 1 and
64mA at logic 0 (guaranteed TTL levels). See datasheet at the end of
the manual for the details. This will support standard SSR and other
devices. Also, there is an option available for the +/-24mA registers
with guaranteed 4.2V output at 24mA, contact factory for the details.
ESSI
The Motorola 56301 DSP contains two High-Speed Enhanced serial
interfaces called ESSI. The PowerDAQ DIO board allows limited
buffered and unlimited register-based access depending upon the
board's operational mode. Each ESSI port contains three transmitters
and one receiver and has a maximum operational speed of 16.5 Mbit/s.
The slowest output bit rate based on DSP’s 66MHz clock is 16113bit/s.
In the combination with the PowerDAQ DIO software, the ESSI
subsystem can be used for High-Speed communication tasks. ESSI port
itself is an extremely flexible and may be adapted to the most of the
high-speed serial synchronous protocols available.
DSP Interrupt lines
Motorola DSP56301 is a powerful processor utilizing advanced Harvard
architecture. One of the features included on this processor is four
high-speed external interrupt lines. OMEGA ENGINEERING is pleased to
pass this feature along with the others to our customers.
Interrupt lines called IRQA/IRQB/IRQC/IRQD acts as
a part of initial system boot process. Those lines
must be properly pulled up or down (or left
unconnected/tri-stated) during the system boot-up
sequence. Following recommendations must be met
to allow you PC to boot properly. When IRQx lines
are used on the PowerDAQ: PD2-DIO revision I and
II : IRQA=1, IRQB / IRQC / IRQD = 0. All other
PowerDAQ DIO boards require IRQA=1, IRQB=0,
IRQC=0, IRQD = 1.
TIP