Micromega uM-FPU64 User manual

uM-FPU64
Floating Point Coprocessor
28-pin Breakout Board
Introduction
The uM-FPU64 28-pin breakout board has all of the required connections, and provides access to all uM-
FPU64 pins. It can be used as a development board or for permanently mounting in a project.
The features include:
• all required connection for the uM-FPU64
• interface selector and connector with resistors for SPI or I2C connections
• serial connector for access to SERIN and SEROUT pins
• serial connector is compatible with SparkFun FDTI 3.3V Basic Breakout and Parallax PropPlug
• Power or Busy Status LED
• space provided for RTC oscillator and capacitors
• breakout connector for D0-D4
• breakout connector for D5-D8 and AN0-AN5
• optional I2C pull-up resistors for D0 and D1
•board can be powered from USB during development
Bare uM-FPU64 28-pin Breakout Board
Micromega Corporation 1 Revised 2013-07-03

Micromega Corporation 2 uM-FPU64 28-pin Breakout Board
Installing the Required Components
The following components are required for all configurations.
1 - 28-pin socket for uM-FPU64
1 - 10uF Tantalum capacitor (low ESR)
2 - 0.1 uF capacitors
2 - 10K resistors
1 - LED (note: + anode (long lead) is on the left)
various 0.1” headers
uM-FPU64
.1uF
.1uF
10 uF
D4 D3 D2 D1 D0 GND 3.3V
DTR
RXI
TXO
CTS
GND
3.3V
RES
GND RES EN
3.3V
GND
SCLK
SOUT
SIN
/SS
SCL
SDA
GND
GND MCL AN0 AN1 D5 BSYD6 D8 D7 GND
POWER
FPUSER
I2C SPISEL
D1-I2C DO-I2C
10K
22pF
22pF 32.768 kHz
10K
4.7K 4.7K
1K
4.7K4.7K
uM-FPU64
28-pin
330 330
Male or female headers can be installed for each of the breakout connectors and jumpers. The following photo
shows the breakout board after the required components and headers have been installed, and a right-angle
header has been installed for the serial connector. See the Serial Connection section for additional information
regarding the serial connector.
Power Selector and LED Resistor
The breakout board can be configured to draw power from the serial connector 3.3V pin, or the interface
connector 3.3V pin. The interface connector should be used for power when connecting the uM-FPU64 to
other components, since the serial connector can only supply a limited amount of current. Using the serial
connector to supply power is convenient for development, since no external power supply is required, but care
should be taken to ensure that the current requirements of your circuit are within the limits that can be provided
by the serial connection.
The LED can be configured as a power on indicator, or as a busy indicator, depending on the placement of the

Micromega Corporation 3 uM-FPU64 28-pin Breakout Board
330 ohm resistor. When configured for power on, the LED turns on whenever 3.3V is applied to the VDD pin.
When configured as a busy indicator, the LED turns on when the /BUSY pin is low.
POWER
FPUSER
POWER
FPUSER
Power from Serial Connector - 3.3V pin
Power from Interface Connector - 3.3V pin
uM-FPU64
.1uF
.1uF
10 uF
D4 D3 D2 D1 D0 GND 3.3V
DTR
RXI
TXO
CTS
GND
3.3V
RES
GND RES EN
3.3V
GND
SCLK
SOUT
SIN
/SS
SCL
SDA
GND
GND MCL AN0 AN1 D5 BSYD6 D8 D7 GND
POWER
FPUSER
I2C SPISEL
D1-I2C DO-I2C
10K
22pF
22pF 32.768 kHz
10K
4.7K 4.7K
1K
4.7K4.7K
uM-FPU64
28-pin
330 330
Power Selector
LED Resistor
330 330
330 330
330 330
LED shows Power On
LED Shows Busy Status
No LED connection
SPI Interface
To configure the board for using an SPI interface, set the SEL jumper and add the 1K resistor if using a 2-wire
interface. The microcontroller connections are shown for each type of SPI interface.
uM-FPU64
.1uF
.1uF
10 uF
D4 D3 D2 D1 D0 GND 3.3V
DTR
RXI
TXO
CTS
GND
3.3V
RES
GND RES EN
3.3V
GND
SCLK
SOUT
SIN
/SS
SCL
SDA
GND
GND MCL AN0 AN1 D5 BSYD6 D8 D7 GND
POWER
FPUSER
I2C SPISEL
D1-I2C DO-I2C
10K
22pF
22pF 32.768 kHz
10K
4.7K 4.7K
1K
4.7K4.7K
uM-FPU64
28-pin
330 330
SEL Jumper
Interface Connector
and Resistors
I2C SPISEL
Select SPI Interface

Micromega Corporation 4 uM-FPU64 28-pin Breakout Board
SPI Bus Interface
No resistors are installed when using an SPI Bus interface.
1K
4.7K4.7K
3.3V
GND
SCLK
SOUT/SDA
SIN/SCL
/SS
Interface Connector
3.3V
GND
SCK
MISO
MOSI
/SS
Microcontroller
SPI 3-wire Interface
No resistors are installed when using an SPI 3-wire interface.
1K
4.7K4.7K
3.3V
GND
SCLK
SOUT/SDA
SIN/SCL
/SS
Interface Connector
3.3V
GND
SCK
MISO
MOSI
GND
Microcontroller
SPI 2-wire Interface
The 1K resistor is installed when using an SPI 2-wire interface.
1K
4.7K4.7K
3.3V
GND
SCLK
SOUT/SDA
SIN/SCL
/SS
Interface Connector
3.3V
GND
CLK
N/C
DATA
GND
Microcontroller

Micromega Corporation 5 uM-FPU64 28-pin Breakout Board
I2C Interface
To configure the board for using an I2C interface, set the SEL jumper and configure the pull-up resistors as
required. The microcontroller connections are shown.
uM-FPU64
.1uF
.1uF
10 uF
D4 D3 D2 D1 D0 GND 3.3V
DTR
RXI
TXO
CTS
GND
3.3V
RES
GND RES EN
3.3V
GND
SCLK
SOUT
SIN
/SS
SCL
SDA
GND
GND MCL AN0 AN1 D5 BSYD6 D8 D7 GND
POWER
FPUSER
I2C SPISEL
D1-I2C DO-I2C
10K
22pF
22pF 32.768 kHz
10K
4.7K 4.7K
1K
4.7K4.7K
uM-FPU64
28-pin
330 330
SEL Jumper
Interface Connector
and Resistors
I2C SPISEL
Select I2C Interface
1K
4.7K4.7K
1K
4.7K4.7K
No Pull-ups Pull-ups
3.3V
GND
SCLK
SOUT/SDA
SIN/SCL
/SS
Interface Connector
3.3V
GND
N/C
SDA
SCL
N/C
Microcontroller
Serial Connection
The serial connector is used to connect to the SERIN and SEROUT pins of the uM-FPU64. The pinout of the
connector has been designed to be compatible with two commonly available USB to serial interface boards:
SparkFun FDTI Basic Breakout - 3.3V (SparkFun part number DEV-08772)
A 6-pin right-angle 0.1” male header should be installed in the outer six holes for the SparkFun
FDTI Basic Breakout.
Parallax Prop Plug (Parallax Item #32201)
A 4-pin right-angle 0.1” male header should be installed in the inner four holes for the Parallax
Prop Plug.
Other 3.3V USB to serial boards can also be used, but will likely require some custom wiring to
change the pinout to be compatible with one of the serial connectors.
A 10K pull-down resistor is connected to the SERIN pin, so if nothing is plugged into the serial
connector pins when the uM-FPU64 in reset, the debug monitor will be disabled.

Micromega Corporation 6 uM-FPU64 28-pin Breakout Board
uM-FPU64
.1uF
.1uF
10 uF
D4 D3 D2 D1 D0 GND 3.3V
DTR
RXI
TXO
CTS
GND
3.3V
RES
GND RES EN
3.3V
GND
SCLK
SOUT
SIN
/SS
SCL
SDA
GND
GND MCL AN0 AN1 D5 BSYD6 D8 D7 GND
POWER
FPUSER
I2C SPISEL
D1-I2C DO-I2C
10K
22pF
22pF 32.768 kHz
10K
4.7K 4.7K
1K
4.7K4.7K
uM-FPU64
28-pin
330 330
Serial
Connector
DTR
RXI
TXO
CTS
GND
3.3V
RES
GND
DTR
RXI
TXO
CTS
GND
3.3V
RES
GND
SparkFun
FDTI Basic 3.3V
Parallax
Prop Plug
Example using FDTI Basic Breakout - 3.3V

Micromega Corporation 7 uM-FPU64 28-pin Breakout Board
Other Connections
uM-FPU64
.1uF
.1uF
10 uF
D4 D3 D2 D1 D0 GND 3.3V
DTR
RXI
TXO
CTS
GND
3.3V
RES
GND RES EN
3.3V
GND
SCLK
SOUT
SIN
/SS
SCL
SDA
GND
GND MCL AN0 AN1 D5 BSYD6 D8 D7 GND
POWER
FPUSER
I2C SPISEL
D1-I2C DO-I2C
10K
22pF
22pF 32.768 kHz
10K
4.7K 4.7K
1K
4.7K4.7K
uM-FPU64
28-pin
330 330
RTC Crystal
D0/D1 I2C Pull-ups
D0/D1 I2C Pull-ups
The D0/D1 pull-up resistors are provided to facilitate using these pins for connecting devices to a local I2C bus.
Jumpers D0-I2C and D1-I2C are provided to enable or disable the pull-up resistors.
4.7K 4.7K
4.7K 4.7K
Not Enabled
Enabled
D1-I2C DO-I2C
D1-I2C DO-I2C
RTC Crystal Oscillator
If the uM-FPU64 real-time clock is used, the 32.768 kHz crystal and two 22pF capacitors must be installed.
22pF
22pF 32.768 kHz
22pF
22pF
D0-D4 Breakout Connector
A 7-pin connector is provided for the D0-D4 pins.
D4 D3 D2 D1 D0 GND 3.3V
PCB Label uM-FPU64 Pin
D4 D4/RTC
D3 D3
D2 D2
D1 D1
GND VSS
3.3V VDD

Micromega Corporation 8 uM-FPU64 28-pin Breakout Board
A0-A5 and D5-D8 Breakout Connector
A 10-pin connector is provided for the A0-A5 and D5-D8 pins. The /MCLR and /BUSY pins are also brought
out to this connector.
GND MCL AN0 AN1 D5 BSYD6 D8 D7 GND
PCB Label uM-FPU64 Pin
GND VSS
MCL /MCLR
AN0 AN0/VREF+
AN1 AN1/VREF-
D5 D5/AN2
D6 D6/AN3
D7 D7/AN4
D7 D8/AN5
BSY /BUSY
GND VSS
Note: Since /MCLR is connected to 3.3V through a 10K pull-up resistor, the uM-FPU64 can be
reset by briefly connecting the MCL pin to ground. Since the GND pin is next to the MCL pin,
a post shunt can easily be used to briefly connect MCL to GND.
GND Connector
Two extra ground pins are provided.
GND
Reset Enable Jumper
This option connects the CTS pin from the serial connector to the /MCLR pin. This jumper should not be
installed, since this capability is not currently supported by the the uM-FPU64 IDE.
RES EN
Schematic Diagram
A schematic diagram is available as a separate document entitled.
See: uM-FPU64 28-pin Breakout Schematic.pdf

Micromega Corporation 9 uM-FPU64 28-pin Breakout Board
Parts List
The parts for the uM-FPU64 breakout board are listed below, with Digi-Key part numbers included for reference
purposes. All of the parts can be replaced with equivalent parts from other suppliers, and many of the parts may
already be in your parts bin. Some parts can be omitted depending on the interface connection and the options
selected.
1. The 4.7K resistors should only be installed if the I2C interface is used, and pull-ups
are not already provided by the connecting device.
2. The 1K resistor should only be installed if the 2-wire SPI interface is used.
3. The crystal and 22 pF capacitors are only required if the real-time clock is used.
Further Information
See the Micromega website (http://www.micromegacorp.com) for additional information regarding the uM-FPU64
floating point coprocessor, including:
uM-FPU64 Datasheet
uM-FPU64 Instruction Set
Qty
1
1
2
2
4
1
1
1
1
2
1
1
4
Description
Socket, 28-pin
Capacitor, 10 uF Tantalum
Capacitor, 0.1 uF Ceramic
Resistor, 10K 1/8W
Resistor, 4.7K 1/8W
(see note 1)
Resistor, 1K 1/8W
(see note 2)
Resistor, 330 1/8W
LED 3mm Green Diffused
Crystal, 32.768 kHz
(see note 3)
Capacitor, 22 pF Ceramic
(see note 3)
Header, 0.1” Right-angle 40-position
6-pin or 4-pin
Header, 0.1” Straight 40-position
10-pin, 7-pin, 6-pin, 3-pin, 3-pin, 2-pin
Post Shunt, 0.1” Low-profile
Use
uM-FPU64
Power
Power
/MCLR pull-up
SERIN pull-
down
I2C pull-ups
2-wire SPI
Power/Busy
LED
Power/Busy
LED
RTC
RTC
Serial
Connector
Connectors
and Jumpers
Jumpers
Digi-Key Part Number
ED3328-ND
478-1839-ND
478-3192-ND
CF18JT10K0CT-ND
CF18JT4K70CT-ND
CF18JT1K00CT-ND
CF18JT330RCT-ND
516-1293-ND
X1124-ND
490-3708-ND
S1111EC-40-ND
S1012EC-40-ND
A26232-ND