Digilent 410-185P-KIT - Manual (Page 3)

Cerebot MC7 Reference Manual
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In system programming and debuggin is
accomplished using a programmer/debugger
circuit licensed from Microchip. Either MPLAB
version 8.63 or later or MPLAB-X is required
for its operation. The licensed debugger is
accessed via USB, using connector J13. This
connector is a micro-USB connector on the
upper left corner of the board. The provided
USB cable should be connected from J13 to a
USB port on the development PC for access to
the board.
When creating a new project, use the
Configure.Select Device menu to specify the
dsPIC device in use. Ensure that the device is
set to dsPIC33FJ128MC706A.
To use the on-board programming/debugging
circuit it must be selected as the debugger or
programmer. Use the Debugger.Select Tool
menu, or the Programmer.Select Tool menu,
and select “Licensed Debugger” as the
programmer or debugger.
The dsPIC microcontroller used on the Cerebot
MC7 uses a two wire interface for in-system
programming and debugging. There are three
alternative pairs of pins that can be used for
this purpose. The Cerebot MC7 is designed to
use signal pair 1, PGEC1/PGED1, for the
connection to the licensed debug circuit. This
selection is controlled by configuration bits
programmed when a firmware image is
programmed into the board. This is selected
using configuration macros provided with the
Microchip C30 compiler. A statement similar to
this should appear in the main program module
of the project:
/* Use PGC1/PGD1 for programming and
debugging
*/
_FICD(ICS_PGD1 & JTAGEN_OFF);
Refer to the dsPIC device data sheet, the
appropriate section of the dsPIC33F Family
Reference Manual and the C30 compiler
documentation for more information.
Board Power Supply
Switch SW1, in the lower left corner of the
board is the power switch. Place this switch in
the ON position to turn on board power and in
the OFF position to turn off board power.
The Cerebot MC7 board has three power
supplies.
One power supply is used to regulate power
for the main circuitry on the Cerebot MC7
board. This supply provides power to the 5V
peripherals on the board, such as the CAN
transceiver and provides the regulated 3.3V to
power the microcontroller and most of the
peripherals on the board. This supply requires
a regulated 5V input.
A second power supply is used to provide an
independent supply for the licensed debugger
circuit. This provides power to the debug circuit
as soon as the power switch is turned on. This
power supply uses a Microchip MCP1801 low
dropout regulator.
The USB specification requires that USB
devices not draw more than 100mA of current
until they have enumerated on the USB bus
and requested more current from the host. To
meet this specification, the debug circuit turns
on main board power by driving the PWR_ON
signal high after successfully enumerating on
the USB bus. The bus labeled on the
schematic as BRD5V0 is switched on when
this occurs. The BRD5V0 bus powers the input
to the primary voltage regulator, the power
supply voltage for the CAN transceiver, and
the 5V0 side of the power select jumpers for
the Pmod connectors.
The third power supply is a 5V switching
voltage regulator that can produce 5V at 4A
from an external source between 5V and 24V.
This power supply can be used to supply the
regulated 5V input to the main board power
supply, and also can provide 5V power to
power hobby servos connected to the servo
connectors. This switching regulator allows
single supply operation of the Cerebot MC7