BL4S200 User’s Manual
38
For best performance, the bias and termination resistors in a multidrop network should
only be enabled on both end nodes of the network. Disable the termination and bias resis-
tors on any intervening BL4S200 units in the network by removing both jumpers from
header JP6.
TIP:
Save the jumpers for possible future use by “parking” them across pins 1–3 and 4–6
of header JP7. Pins 3 and 4 are not otherwise connected to the BL4S200.
3.3.3 Programming Port
The RabbitCore module on the BL4S200 has a 10-pin programming header. The program-
ming port uses the Rabbit 4000 or Rabbit 5000 Serial Port A for communication, and is
used for the following operations.
•
Programming/debugging
•
Cloning
The programming port is used to start the BL4S200 in a mode where the BL4S200 will
download a program from the port and then execute the program. The programming port
transmits information to and from a PC while a program is being debugged.
The Rabbit 4000 or Rabbit 5000 startup-mode pins (SMODE0, SMODE1) are presented
to the programming port so that an externally connected device can force the BL4S200 to
start up in an external bootstrap mode. The BL4S200 can be reset from the programming
port via the
/EXT_RSTIN
line.
The Rabbit microprocessor status pin is also presented to the programming port. The status
pin is an output that can be used to send a general digital signal.
NOTE:
Refer to the
Rabbit 4000 Microprocessor User’s Manual
and the
Rabbit 5000
Microprocessor User’s Manual
for more information related to the bootstrap mode.
electronic components distributor
