AT91EB40 Atmel, AT91EB40 Datasheet - Page 16

• Manufacturer Part Number: AT91EB40
• Description: AT91 ARM X40 SERIES EVAL KIT
• Manufacturer: Atmel

Specifications of AT91EB40

• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

Circuit Description
4.6
4.7
4.8
4-2
JTAG Interface,
Reset, Interrupts
and LEDs
Serial Interface
Layout Drawing
The voltage regulator provides 3.3V to the board and will light the red POWER LED
when operating. Power can be applied via the 2.1 mm connector to the regulator in
either polarity because of the diode rectifying circuit. The regulators can tolerate supply
transients to 30V although they will shut down without damage if they overheat.
An ARM
EmbeddedICE interface (using an EmbeddedICE to Multi-ICE adapter) or Multi-ICE
interface to the JTAG inputs on the AT91. This allows code to be developed on the
board without the use of system resources such as memory and serial ports.
The IRQ, FIQ and TIOB0 switches are debounced and buffered. A supervisory circuit
has been included in the design to detect and consequently reset the board when the
3.3V supply voltage drops below 3.08V. It also provides a debounced reset signal.
The schematic also shows LEDs 1, 2 and 3, which are for general purpose use and are
connected to timer (or I/O) pins TIOA0/P1, TIOA1/P4 and TIOB0/P2.
Two 9-way D-type connectors (J5/6) are provided for serial port connection. Serial portA
(J5) is used primarily for host PC communication and is a DB9 female connector. TXD
and RXD are swapped so that a straight-through cable can be used. CTS and RTS are
connected together, as are DCD, DSR and DTR.
Serial port B (J6) is a DB9 male connector with TXD and RXD obeying the standard
RS-232 pinout. Apart from TXD, RXD and ground, the other pins are not connected.
RS-232 level conversion is provided by a MAX3223 device (U13) and associated bulk
storage capacitors.
The layout diagram schematic shows an approximate floorplan for the board. This has
been designed to give the lowest board area, while still providing access to all test
points, links and switches on the board. See Figure 6-2.
The size is approximately 4.5 inches square with four mounting holes, one at each cor-
ner, into which feet are attached. The board has two signal layers and two power
planes.
®
-standard 20-pin box header (J2) is provided to enable connection of an
AT91EB40 Evaluation Board User Guide