NXP Semiconductors DRM050 User manual

MOTOROLA.COM/SEMICONDUCTORS
M68HC08
Microcontrollers
DRM050/D
Rev. 0, 09/2003
2.4-GHz Wireless
Designer Reference
Optical Mouse and
Manual
Multimedia Keyboard
Solution
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DRM050 — Rev 0 Designer Reference Manual
MOTOROLA 3
Motorola and the Stylized M Logo are registered trademarks of Motorola, Inc.
DigitalDNA is a trademark of Motorola, Inc.
This product incorporates SuperFlash® technology licensed from SST. © Motorola, Inc., 2003
2.4-GHz Wireless Optical Mouse and
Multimedia Keyboard Solution
Designer Reference Manual — Rev 0
By: Dennis Lui
Ernest Chan
W.S. Wong
Applications Engineering
Microcontroller Division
Hong Kong
To provide the most up-to-date information, the revision of our documents on
the World Wide Web will be the most current. Your printed copy may be an
earlier revision. To verify you have the latest information available, refer to:
http://motorola.com/semiconductors
The following revision history table summarizes changes contained in this
document. For your convenience, the page number designators have been
linked to the appropriate location.
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Revision History
Designer Reference Manual DRM050 — Rev 0
4 Revision History MOTOROLA
Revision History
Section Page Description of Change
Throughout NA Initial Release
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DRM050 — Rev 0 Designer Reference Manual
MOTOROLA 5
Designer Reference Manual — DRM050
Table of Contents
Section 1. System Overview
1.1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
1.2 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
1.3 System Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
1.4 Transmit and Receive. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
Section 2. RF Front End
2.1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
2.2 Functional Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
2.3 RF Transceiver Module RFW102 . . . . . . . . . . . . . . . . . . . . . . .12
2.4 Interface IC RFW-D100 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
2.5 Antenna and PCB Specification . . . . . . . . . . . . . . . . . . . . . . . .15
Section 3. Optical Mouse Transmitter
3.1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17
3.2 System Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17
3.2.1 Microcontroller JB8. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18
3.2.2 Optical Mouse Sensor . . . . . . . . . . . . . . . . . . . . . . . . . . . . .18
3.2.3 RF Transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
3.2.4 DC/DC Converter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
Section 4. Mouse Transmitter Firmware
4.1 MAC Layer Protocol . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21
4.2 Application Firmware Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
4.3 Power Management for the Mouse. . . . . . . . . . . . . . . . . . . . . .23
4.4 Output Buffer Format for the RF Packet. . . . . . . . . . . . . . . . . .24
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Designer Reference Manual DRM050 — Rev 0
6MOTOROLA
Section 5. Multimedia Keyboard Transmitter
5.1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27
5.2 System Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27
5.2.1 Microcontroller LK24 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28
5.2.2 RF Transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28
5.2.3 DC/DC Converter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29
Section 6. Keyboard Transmitter Firmware
6.1 Firmware Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
6.2 Output Buffer Format for Keyboard RF Packet. . . . . . . . . . . . .32
Section 7. USB Receiver
7.1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35
7.2 System Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .35
7.2.1 Microcontroller JB16. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36
7.2.2 RF Transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36
7.2.3 Voltage Regulator. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .37
Section 8. Receiver Firmware
8.1 Receiver Firmware Structure . . . . . . . . . . . . . . . . . . . . . . . . . .39
8.2 USB Report. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .41
8.2.1 Input Report Example. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43
8.3 Remote Wakeup. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44
Section 9. Testing and Customization
9.1 Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
9.2 Customization. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
9.2.1 Hardware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45
9.2.1.1 Optical Mouse Transmitter. . . . . . . . . . . . . . . . . . . . . . . .45
9.2.1.2 Keyboard Transmitter . . . . . . . . . . . . . . . . . . . . . . . . . . .46
9.2.1.3 USB Receiver . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46
9.2.1.4 RF Circuitry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46
9.2.2 Firmware . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46
9.2.2.1 Mouse Transmitter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46
9.2.2.2 Keyboard Transmitter . . . . . . . . . . . . . . . . . . . . . . . . . . .46
9.2.2.3 Receiver. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46
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DRM050 — Rev 0 Designer Reference Manual
MOTOROLA System Overview 7
Designer Reference Manual — DRM050
Section 1. System Overview
1.1 Introduction
This manual describes a reference design of a 2.4-GHz Universal Serial
Bus Wireless Optical Mouse and Multimedia Keyboard solution by using
the MC68HC908JB8, MC68HC908LK24, and MC68HC908JB16.
The whole system consists of a wireless mouse, a wireless keyboard
and a USB receiver. The wireless communication link is developed in the
worldwide unlicensed Industrial, Scientific, and Medical (ISM) band of
2400–2483 MHz. All hardware schematic diagrams and firmware source
codes are available as reference materials.
1.2 Features
• High speed RF link in 2.4-GHz ISM band
• Windows 98, Windows 2000, and Windows XPCompatible1
• USB 2.0 Low Speed Compliance
• 1 Mbps transmission data rate
• 10 to 20 meter communication distance
• RF front end and Media Access Control (MAC) designs are based
on RFWaves chipset and protocol
1. Windows 98, Windows 2000 and Windows XP are trademarks of Microsoft Corporation in the
U.S. and other countries.
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System Overview
Designer Reference Manual DRM050 — Rev 0
8 System Overview MOTOROLA
1.3 System Overview
Figure 1-1. System Overview
The system consists of three functional devices, a wireless optical
mouse using the MC68HC908JB8 (hereafter referred as JB8, production
version uses the low voltage MC68HC08JT8), a wireless multimedia
keyboard using the MC68HC908LK24 (hereafter referred as LK24), and
the wireless receiver using the MC68HC908JB16 (hereafter referred as
JB16).
The basic structure and functional blocks for each device are similar and
consist of a RF transceiver module for half duplex transmission in
2.4-GHz frequency band, a baseband IC for link layer access control and
protocol handling. The overall system operation, I/O interface, and
power management are controlled by MCU.
Based on the number of I/O pins, voltage operation, and memory size
requirements, the JB8 and LK24 are chosen for wireless mouse and
SPI bus
USB
Parallel
Address &
Data bus
MCU
908LK24 /
908JB8
Keyboard/
Mouse
Interface
RFW-102
Module
Antenna
RFW-D100
MAC
MCU
908JB16 PC Host
Interface
RFW-102
Module
Antenna
RFW-D100
MAC
SPI bus
Parallel
Address &
Data bus
I/O Detect
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System Overview
Transmit and Receive
DRM050 — Rev 0 Designer Reference Manual
MOTOROLA System Overview 9
keyboard designs. The JB16 is specially designed for USB wireless
application. It has high processing power and large memory size to
handle overall data traffic control for multiple input devices.
1.4 Transmit and Receive
In data transmission, the data generated from the key matrix in a
keyboard or displacement detection/button status data in mouse
application is detected by MCU and sent to the baseband IC in a parallel
format. All kinds of media access, link layout control, and data
conversion in serial format are handled by the baseband IC. The final
data in serial format is transmitted by the RF module at 2.4 GHz.
In data reception, the data received from RF module is decoded with
corresponding protocol, and the serial packet data will be converted into
parallel format again in baseband processing. The final data in parallel
format will be captured by MCU and sent to the PC host through the USB
interface.
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System Overview
Designer Reference Manual DRM050 — Rev 0
10 System Overview MOTOROLA
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DRM050 — Rev 0 Designer Reference Manual
MOTOROLA RF Front End 11
Designer Reference Manual — DRM050
Section 2. RF Front End
2.1 Introduction
2.4-GHz RF links are designed for wireless communication media for
this application. The RF font end of the USB receiver, mouse, and
keyboard are the same. The front end is a half duplex direct sequence
spread spectrum (DSSS) radio transceiver chipset, intended for use in
the world wide unlicensed Industrial, Scientific, and Medical (ISM) band
of 2400–2483.5MHz. The front end chipset mainly consist of two parts,
the transceiver module RFW102 and the interface IC RFW-D100. CSMA
is used as the communication protocol in between the USB receiver, the
keyboard, and mouse.
2.2 Functional Description
The complete solution of the RF transceiver consists of an RF
transceiver module RFW102 and a link interface IC RFW-D100. The
RFW-D100 links the MCU and the transceiver module. When data is
being transmitted from the mouse or keyboard, the transmit data from
the MCU is passes into the interface IC. In the interface IC, the data will
be converted from parallel type to serial type. Also it will be coded with
packet address and error checking.
The serial data will then pass to the RF transceiver and ASK modulates
into IF frequency 488 MHz. The modulated data will be DSSS spreading
and up-converts into 2.4 GHz RF signal for transmission.
When the RF signal is received by the USB receiver, it is
down-converted into IF frequency and DSSS de-spreading into ASK IF
signal. Then, the ASK IF signal will demodulate into serial data out of the
RF transceiver module RFW102.
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RF Front End
Designer Reference Manual DRM050 — Rev 0
12 RF Front End MOTOROLA
The received serial data will pass into the interface IC RFW-D100, in
which it will be converted to parallel data for the MCU.
2.3 RF Transceiver Module RFW102
The RFW102 transceiver module is a short-range, half-duplex wireless
radio transceiver. The transceiver is intended for use in the unlicensed
ISM band of 2400–2483.5 MHz.
The transceiver module provides a peak output power of 2 dBm and data
rate up to 1Mbps. Power consumption during transmit is extremely low,
(21 mA in 1Mbps, 28 mA in 1 kbps), which is directly dependent on the
bit transfer rate. During standby mode, the transceiver consumes almost
no power and features an extremely short wake up time of 20 ms.
The communication link between the transceivers is a Direct Sequence
Spread Spectrum (DSSS) pulse pipe. The modulation scheme is 100%
MCU + GPIOs
(JB8/LJ24)
3.3V
DC-DC
Battery
Keyboard/ Mouse
RFW-102
Modul e
Antenna
RFW-D100
Serial to parallel interface
Parallel Add/Data bus
6-24MHz Xtal
Mouse & Keyboard
MCU + GPIOs
(JB8/LJ24)
3.3V
DC-DC
Battery
Keyboard/ Mouse
RFW-102
Modul e
Antenna
RFW-D100
Serial to parallel interface
Parallel Add/Data bus
6-24MHz Xtal
Mouse & Keyboard
MCU + GPIOs
(JB8/LJ24)
3.3V
DC-DC
Battery
3.3V
DC-DC
Battery
Keyboard/ Mouse
RFW-102
Modul e
Antenna
RFW-D100
Serial to parallel interface
Parallel Add/Data bus
6-24MHz Xtal
Mouse & Keyboard
MCU + USB–
I/F
(JB16)
Power Circuit
DC-DC
3.3V
RFW-102
Module
Antenn
a
RFW-D100
Serial to parallel interface
Parallel Add/Data bus
6-24MHz
USB
+5V
Xtal
USB Dongle
MCU + USB–
I/F
(JB16)
Power Circuit
DC-DC
3.3V
RFW-102
Module
Antenn
a
RFW-D100
Serial to parallel interface
Parallel Add/Data bus
6-24MHz
USB
+5V
Xtal
USB Dongle
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RF Front End
RF Transceiver Module RFW102
DRM050 — Rev 0 Designer Reference Manual
MOTOROLA RF Front End 13
Amplitude Shift Keying (ASK). The spreading modulation scheme is a
Bi-Phase modulation where each bit has a 13-bit Barker series.
Below are the key features of the transceiver module:
• 2.4-GHz unlicensed ISM band operation
• 1 Mbps data rate
• Sample 3 line digital interface
• Low power consumption
• +2 dBm typical peak output transmission power
• –80 dBm typical sensitivity
• Typical standby current of 2.6 mA
• Compiles with FCC regulation
• Wide range operating voltage (2.7 V–3.6 V)
• Direct Sequence Spread Spectrum (DSSS) 11 dB processing gain
• Short signal acquisition time (1.2 ms)
The transceiver has a fully digital serial I/O interface providing a simple
3-line interface. Tx/Rx is for controlling of the transceiver work in transmit
or receive mode. Act is used for switching the transceiver between
working mode and sleep mode. Data IO is the data transfer channel.
The transceiver chipset includes three chips.
• RFW24 — An RFIC performs all of the timing, amplifying,
switching, transmitting, and receiving functions.
• RFW488C — A 4-pin SAW correlator, which is used as a direct
sequence spread spectrum spreading and de-spreading element.
• RFW488R — A 1-port SAW resonator, which serves as the
system oscillation source.
For detailed information on the internal implementation of the transceiver
module, please refer to the data sheet about the RFW102 from
RFWaves website:
http://www.rfwaves.com
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RF Front End
Designer Reference Manual DRM050 — Rev 0
14 RF Front End MOTOROLA
2.4 Interface IC RFW-D100
The RFW-D100 is a complimentary IC to the RFW-102 module. It
provides an MCU with a parallel interface to the RFW-102 transceiver
module and other features that enable implementing a protocol suitable
for wireless communication with a small burden on the MCU.
In HID application, the MCU is in charge of the MAC layer protocol. The
RFW-D100 is used to reduce the real-time demands of the MCU
handling the MAC protocol. It converts the fast serial input to 8-bit words,
which are much easier for 8-bit MCUs to work with. Also, it buffers the
input through a 16-byte FIFO, giving the MCU access the RFW-D100
efficiently. Instead of reading one byte per interrupt, the MCU can read
up to 16 bytes in each interrupt.
Below are the features of the RFW-D100 interface IC:
• Provides parallel interface with the RFW102 modem
• Serial to parallel conversion of the RFW102 interface
• Input FIFO (RX_FIFO)
• Output FIFO (TX_FIFO)
• Preamble Correlation
• Packet Address Filter
• CRC calculation
• Watchdog Timer driven by internal RC oscillator
• Power saving mode: Idle, Power-down.
• Receiver signal strength indication (RSSI)
For detailed information on the RFW-D100, please refer to the data
sheet about the RFW-D100 from the RFWaves website:
http://www.rfwaves.com
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RF Front End
Antenna and PCB Specification
DRM050 — Rev 0 Designer Reference Manual
MOTOROLA RF Front End 15
2.5 Antenna and PCB Specification
The antenna interface of the RFWaves module RFW102 is 200 Ω
differential. For matching and placement of different antenna, refer to the
data sheet of the specific antenna you are using.
The reference antenna of the RFWaves transceiver module RFW102-M
used here is a special design printed circuit board differential loop
antenna. The purpose of this design is aimed at low cost, small form
factor, and high directivity design.
For the dimension and PCB specification of the antenna board, please
refer to documents which can be download from RFWaves website:
http://www.rfwaves.com
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RF Front End
Designer Reference Manual DRM050 — Rev 0
16 RF Front End MOTOROLA
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DRM050 — Rev 0 Designer Reference Manual
MOTOROLA Optical Mouse Transmitter 17
Designer Reference Manual — DRM050
Section 3. Optical Mouse Transmitter
3.1 Introduction
The JB8 has 8K Flash memory, 3-MHz bus processing power, 16-bit
2-channel timer module, and appropriate number of I/O pins makes this
MCU suited for this 2.4-GHz Wireless Optical Mouse application. The
main features of the reference design include:
• 2.4-GHz RF Link
• 1 Mbps data rate
• 800 DPI Resolution
• Smart Power Management
3.2 System Overview
The optical mouse consists of the JB8, the Agilent optical mouse sensor
ADNS-2030, the baseband IC and RF Module from RFWaves, and
DC/DC converter. Figure 3-1 shows the block diagram of the system.
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Optical Mouse Transmitter
Designer Reference Manual DRM050 — Rev 0
18 Optical Mouse Transmitter MOTOROLA
Figure 3-1. Mouse Block Diagram
3.2.1 Microcontroller JB8
The functions of the JB8 are to get the XY displacement from the sensor,
detect the Z displacement, check button status, control the baseband IC
to sending out data, and perform the overall power management.
Three standard left, middle, and right buttons (and two additional buttons
reserved for future development) are implemented.
3.2.2 Optical Mouse Sensor
The AN2030 is a 3-V supply sensor specially design for wireless optical
mouse. The communication between the sensor and the JB8 is through
Serial Peripheral Interface with clock input at the SCLK pin and
bidirection data interface at SDIO pin. The Power Down (PD) pin is used
to power down the sensor when it’s not in use.
ADNS-2030
SCLK
SDIO
PD
XY_LED
IMAGE
SENSOR
(16-pin PDIP)
MC68HC908JB8
Buttons
PTA0
L
M
R
PTA1
PTE0
PTA6
PTA5
PTA2
Z1
(44-pin QFP)
PTE1
PTE2
DATA BUS
ADDRESS / CTL BUS
PTB7-PTB0
PTC7-PTC0
2.4 GHz RF
Transceiver
Module
LOOP
ANTENNA
DGND
L2
R2
PTA4
PTA3
Z2
Baseband
MAC IC
D100
DC/DC Converters
3.3V and 5V
OSC1
OSC2
RST
6MHz
30pF 30pF
X1
100nF
10M
RFD_INT IRQ
Z-axis
Encoder
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Optical Mouse Transmitter
System Overview
DRM050 — Rev 0 Designer Reference Manual
MOTOROLA Optical Mouse Transmitter 19
3.2.3 RF Transmission
The data from the MCU will be transferred to the baseband IC for parallel
to serial packet conversion as well as error checking. The encoded data
will be passed to the RF module for ASK modulation in IF band and
frequency spreading with DSSS scheme. The modulated signal will be
further up-converted into 2.4-GHz ISM band for final transmission.
3.2.4 DC/DC Converter
The power supply for a handheld device should be able to keep the DC
voltage output at a constant level even though the input battery voltage
is continuously dropping down. There are two DC/DC converters; the
3.3-V supply is used for the baseband IC and RF module. The 5-V
supply is only used for the JB8, but it would be eliminated in the final
product when the low-voltage version JT8 is used.
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Optical Mouse Transmitter
Designer Reference Manual DRM050 — Rev 0
20 Optical Mouse Transmitter MOTOROLA
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