PICDEM™ 17 Demonstration Board User’s Guide
DS39024B-page 4 2001 Microchip Technology Inc.
1.4 External FLASH Memory
The PICDEM 17 demonstration board supports all operating modes of the
PIC17C7XX PICmicro® microcontroller. However, the Monitor program uses
the extended microcontroller mode of operation. The FLASH is the
AM29F100T device from AMD configured as 64K x 16. The monitor program
supports downloading code into the FLASH and then running the program.
1.5 Memory Mapping
Since the PIC17C756A is in the extended microcontroller mode, there are
several memory mapped peripherals available to the user. The first is the
eight push-button switches mapped at address FFFCh. The eight LEDs are
mapped at address FFFDh. There are also two signals that provide decoding
for an address of 8 (LE_1) and an address of 16 (LE_2). These signals are
located in the digital prototyping area in the upper right-hand corner of the
board.
1.6 Power Supply
The PICDEM 17 demonstration board provides a different power supply
structure to the user. The only power input capable of powering the entire
board is at the connector J1. Any power supply with a 2.1 mm plug capable of
delivering +9V, up to 1A, unregulated Alternating Current (AC) or Direct
Current (DC) can be used. The digital components on the board are powered
from a LM2940T-5.0 that is capable of supplying 1A of current. This digital
+5V is available in the digital prototyping area in the upper right-hand cor ner
of the board.
The analog section of the PICDEM 17 demonstration board has a separate
power source and voltage reference. A LM78L05 +5V regulator provides 15 0
mA at +5V for the analog circuits. It is also available in the analog prototyping
area in the lower left-hand corner of the board. There is also a precision
+4.096V reference that is connected to the (Analog-to-Digital) A/D as well as
the analog prototyping area.
1.7 Prototyping Areas
The PICDEM 17 demonstration board provides two prototyping area s, one for
analog and one for digital. The PICDEM 17 demonstration board was
designed to fully demonstrate the capabilities of the on-chip A/D converter. In
addition to the separate analog power supply and voltage reference, the
printed circuit board has four layers with two signal layers and a power a nd
ground layer. The analog prototyping area has all A/D channels, analog VDD
and VSS, as well as the voltage reference available to the user. The digital
prototyping area has all other I/O pins, complete 16-bit address bus, dig ital
VDD and VSS, and additional memory mapped peripheral signals.