MAXQUSBJTAG-KIT# Maxim Integrated Products, MAXQUSBJTAG-KIT# Datasheet - Page 4

• Manufacturer Part Number: MAXQUSBJTAG-KIT#
• Description: MAXQ USB JTAG EVAL BOARD
• Manufacturer: Maxim Integrated Products

Specifications of MAXQUSBJTAG-KIT#

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Connectors P3 and P4 are designed to allow hardware
compatibility with previous Maxim EV kit module
designs. Headers P7 and P8 allow convenient probing
of SMBus/I
Connector P5 is used during factory test to program the
MAXQ2000 in-circuit using the JTAG interface. The
connector pinout is compatible with the MAXQ2000 EV
kit’s MAXQ-JTAG-001 board.
LED1 is lit when VDD is powered. LED2, LED3, and LED4
are general-purpose software-controlled indicators, which
also connect to GPIO lines. When driven as inputs, the
output impedance should be less than 6000Ω.
The CMAXQUSB module offers “bit-banged” I
400kHz (full speed, the default) or 100kHz (slow speed).
Optional user-switchable SCL/SDA pullup resistors are
provided on-board. Your PC and its software limits
attainable throughput. The SMBus/I
bursts at rated speed, but there is some variable “dead
time” between transfers due to communications over-
head. Properly written PC software can minimize this
dead time but cannot completely eliminate it.
The CMAXQUSB module offers SPI at up to 8MHz,
using the default pin configuration. All four CPOL/CPHA
modes are supported. Your PC and its software limits
attainable throughput. The SPI bus runs in bursts at
rated speed, but there is some variable “dead time”
between transfers, due to communications overhead.
Properly written PC software can minimize this dead
time but cannot completely eliminate it.
The CMAXQUSB is powered by the host PC’s universal
serial bus (USB). The VDD system voltage can be con-
figured for direct USB 5V power, 3.3V, or 2.5V using
one of two on-board linear regulators. An optional
external 9V DC plug-in transformer (“wall wart”) can be
connected for any EV kit board that requires this unreg-
ulated 9V DC power supply. Both the unregulated
9V DC and regulated VDD power-supply voltages are
provided to the EV kit board on the 2 x 10 (P3) and
2 x 20 (P4) connectors. Current available to a compan-
ion EV kit is 80mA.
During USB suspend, the FT232BM drives the MAX890
into a partially powered mode, bringing VDD up to
CMAXQUSB User’s Guide
4
_______________________________________________________________________________________
General-Purpose Input and Output (GPIO) Pins
Platform Capabilities and Limitations
2
C and SPI bus signals.
SMBus/I
SPI/3-Wire Interface
2
C/2-Wire Interface
2
C bus runs in
Power Supply
2
C at
approximately 1.8V. No commands are sent to the
firmware during this mode, so there is no impact.
However, custom designs not requiring USB suspend
should consider removing the MAX890 to avoid this
problem.
The CMAXQUSB can store a script of commands in its
internal memory to eliminate communication “dead
time.” A script may be repeated up to 256 times, but
branching and decision making are not supported. A
script may also have a maximum of 126 command/data
bytes. Up to 1024 bytes of data may be collected.
SMBus/I
SDA. The CMAXQUSB provides 1.5kΩ pullup resistors,
enabled by setting both circuits of DIP switch SW1
“ON.” If there are pullup resistors already on the bus,
disable the CMAXQUSB’s pullup resistors by setting
both circuits of SW1 “OFF.”
1-Wire is a registered trademark of Maxim Intergrated
Products, Inc.
(underneath
(underneath
JUMPER
JU1 VDD
SELECT
SW1)
SW1)
JU2
JU4
JU5
SMBus/I
J2
J3
2
C requires a pullup resistor on both SCL and
POSITION
2
Closed
Closed
Closed
Scripting and Data Acquisition
Open
Open
Open
Open
2.5V
3.3V
C/2-Wire Bus Pullup Resistors
5V
V
V
V
Factory assembly option:
replaces SW1-1.
Factory assembly option:
replaces SW1-2.
Connects MAXQ2000 P6.2 to
P6.3, supporting the Maxim
1-Wire® interface.
JTAG connector P5 does not
connect to the +5V supply.
JTAG connector P5 connects to
the +5V supply.
Optional higher voltage
unregulated power supply is left
unconnected; connector P1 is
not used.
Enable optional unregulated
power supply from P1 to
connectors P3 and P4.
DD
DD
DD
= 2.5V
= 3.3V
= 5V
FUNCTION
Jumper Tables