Cerebot MC7™ Board Reference Manual
Copyright Digilent, Inc. All rights reserved.
Other product and company names mentioned may be trademarks of their respective owners.
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provide the pull-up resistors. I
2
C bus #2 has permanently connected pull-up resistors. I
2
C bus #1 has selectable
pull-up resistors that can be enabled or disabled via jumper blocks on J5 and J7. The pull-ups are enabled by
installing shorting blocks and are disabled by removing the shorting blocks. The shorting blocks are placed so that
they line up with the SCL and SDA labels on the board. Only one device on the bus should have the pull-ups
enabled.
SC
L
SD
A
SC
L
SD
A
Pull-ups
Enabled
Pull-ups
Disabled
3
V3
G
ND
3
V3
G
ND
Jumper settings for I2C Pull-up resistors.
10 I
2
C EEPROM
The Cerebot MC7 provides one on-board I
2
C device, a Microchip 24LC256 serial EEPROM. This device is connected
to I2C bus #2. The 24LC256 is a 256Kbit (32Kbyte) serial EEPROM device to provide non-volatile memory storage.
The device address for the 24LC256 is 1010000 (0x50).
Refer to the Microchip data sheet for detailed information on the operation of this device.
11 Pmod Connectors
The Cerebot MC7 has three Pmod connectors for connecting Digilent Pmod peripheral modules. Digilent Pmods
are a line of small peripheral modules that provide various kind of I/O interfaces. The Pmod line includes such
things as button, switch and LED modules, connector modules, LCD displays, high current output drivers, and many
others.
There are two styles of Pmod connector: six-pin and twelve-pin. Both connectors use standard pin headers with
100mil spaced pins. The six-pin connectors have the pins in a 1x6 configuration, while the twelve-pin connectors
use a 2x6 configuration. The six-pin connectors provide four I/O signals, ground and a switchable power
connection. The twelve-pin connectors provide eight I/O signals, two power and two ground pins. The twelve-pin
connectors have the signals arranged so that one twelve-pin connector is equivalent to two of the six-pin
connectors. The power connection is switchable between the regulated 3.3V main board supply and the
unregulated input supply.
On the Cerebot MC7, Pmod connector JA is a six pin connector that can be used for general purpose I/O or for
connection to UART1 or SPI1. Connector JB is a twelve pin connector that can be used for general I/O and provides
access to SPI2, and two external interrupts (INT2 and INT3). Connector JC is a twelve pin connector that can be
used for general I/O, plus access to the output compare units and two of the input capture units.
Digilent Pmod peripheral modules can either be plugged directly into the connectors on the Cerebot MC7 or
attached via cables. Digilent has a variety of Pmod interconnect cables available.
