Datasheet
Maxim Integrated
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4
www.maximintegrated.com
MAXQ610 Evaluation Kit
Evaluates: MAXQ610
Infrared (IR) Interface
The MAXQ610 microcontroller provides a dedicated IR
timer/counter module to simplify support for IR communi-
cation. The IR timer/counter implements two pins (IRTX
and IRRX) for supporting IR transmit and receive, respec-
tively. The IRTX output pin can be manipulated high or
low using the IRTXOUT bit of the power control register
(PWCN) when the IRTX function is not enabled. However,
the IRTX pin has no corresponding port pin designation,
so the standard port direction (PD), port output (PO), and
port input (PI) control status bits are not present.
The MAXQ610 EV kit board includes circuitry for both
receiving and transmitting IR signals. The IR source is
diode D1. Its anode is connected to the board’s VDD sup-
ply through an 82Ω resistor, and its cathode is connected
to the MAXQ610’s IRTX pin (pin 39) when jumper JH15 is
installed. The IR receiving circuitry consists of silicon PIN
photodiode D2 and an npn bipolar transistor with biasing
resistors. The photodiode D2 is intended for IR applica-
tions in the 700nm to 1100nm range, and the transistor is
configured as a common emitter amplifier for the diode.
Its collector is connected to the processor’s IRRX pin
(when JH16 is installed), and the emitter is connected
to the processor’s P0.7 (TBB1, pin 10) pin when jumper
JH17 is installed. This allows the processor’s port pin to
be used as an IR receiver-enable signal.
Serial Port Interface
The MAXQ610’s serial ports are both connected to
RS-232 level translators, and these RS-232 level signals
are connected the DB9 connectors (J1 and J2). A number
of jumpers are used to connect various serial signals to
the level translator and configure its operation. Table 1
describes these jumper functions.
Table 1. Jumper Functions
JUMPER SETTING EFFECT
JH1
1-2 Closed Connects pin 3 (FORCEON) of the RS-232 level translator U1 to MAXQ610 pin 28 (port pin P3.5).
2-3 Closed* Connects pin 3 (FORCEON) of the RS-232 level translator U1 to the board’s VDD.
Open Connects pin 3 (FORCEON) to ground.
JH2
1-2 Closed
Connects pin 4 (FFORCEOFF) of the RS-232 level translator U1 to MAXQ610 pin 33 (P3.6).
2-3 Closed*
Connects pin 4 (FORCEOFF) of the RS-232 level translator U1 to the board’s VDD.
Open
Connects pin 4 (FORCEOFF) to ground.
JH3
1-2 Closed Connects pin 7 (T1IN) of the RS-232 level translator U1 to the board’s VDD.
2-3 Closed* Connects pin 7 (T1IN) of the RS-232 level translator U1 to MAXQ610 pin 5 (TX0, P0.2).
Open Pin 7 (T1IN) is oating.
JH4
1-2 Closed Connects pin 8 (T2IN) of the RS-232 level translator U1 to the board’s VDD.
2-3 Closed* Connects pin 8 (T2IN) of the RS-232 level translator U1 to MAXQ610 pin 7 (TX1, P0.4).
Open Pin 8 (T2IN) is oating.
JH5
1-2 Closed* Connects the board’s VDD source to U2’s pin 5 (3.3V OUT).
2-3 Closed Connects the board’s VDD source to GND.
Open VDD is oating.
JH14
Open Disconnects the MAXQ610’s pin 38 (VDD input) from the board’s VDD source.
Closed* Connects the MAXQ610’s pin 38 (VDD input) to the board’s VDD source.
JH15
Open Disconnects the board’s D1 LED IR emitter from the MAXQ610’s pin 39 (IRTX).
Closed* Connects the board’s D1 LED IR emitter to the MAXQ610’s pin 39 (IRTX).
JH16
Open Disconnects the board’s D2 LED IR receiver amplied signal from the MAXQ610’s pin 40 (IRRX).
Closed* Connects the board’s D2 LED IR receiver amplied signal to the MAXQ610’s pin 40 (IRRX).
JH17
Open Disconnects the IR Rx enable from the MAXQ610’s pin 10 (P0.7).
Closed* Connects the IR Rx enable to the MAXQ610’s P0.7 pin 10 (P0.7).