GW Instek GDS-3000 Series User manual

Digital Storage Oscilloscope
GDS-3000 Series
SERIAL DECODE MANUAL
GW INSTEK PART NO. 82DS-SBD00U01
ISO-9001 CERTIFIED MANUFACTURER

October 2010
This manual contains proprietary information, which is protected by
copyright. All rights are reserved. No part of this manual may be
photocopied, reproduced or translated to another language without
prior written consent of Good Will company.
The information in this manual was correct at the time of printing.
However, Good Will continues to improve products and reserves the
rights to change specification, equipment, and maintenance
procedures at any time without notice.
Good Will Instrument Co., Ltd.
No. 7-1, Jhongsing Rd., Tucheng City, Taipei County 236, Taiwan.

TABLE OF CONTENTS
3
Table of Contents
GETTING STARTED........................................................... 5
Activating Optional Software ................. 6
QUICK REFERENCE........................................................... 8
Menu Tree / Operation Shortcuts ..........9
MEASUREMENT.............................................................. 12
Serial Bus ............................................ 13
INDEX............................................................................. 29

4

GETTING STARTED
5
GETTING STARTED
This chapter describes how to install the serial
decode software.
Activating Optional Software ............................................. 6

GDS-3000 Serial Decode User Manual
6
Activating Optional Software
Background The GDS-3000 has Power Analysis software, Serial
bus decoding software (page 13) as well as other
GW Instek software packages as optional extras.
An activation key is required to activate the
software. An activation key is required for each
optional software package.
For the latest files and information regarding the
optional software packages, see the GW Instek
website: www.gwinstek.com
Activation key
filenames
Serial bus decode
activation key
XX.LIS
Steps 1. Insert a USB stick into the front
panel USB port with the activation
keys located in the root directory.
2. Press the Utility key.
3. Press File Utilities from the bottom
menu.
4. The file system appears.

GETTING STARTED
7
5. Use the Variable knob and Select key to select
the activation key from the USB root directory.
When prompted to continue, press the Select
key again.
Files: XX.LIS
Confirm
Activation key
Press B1 on the front panel to see if the
Serial Bus decode activation worked.

GDS-3000 Serial Decode User Manual
8
QUICK REFERENCE
This chapter depicts the serial bus menu tree. Use
them as a handy reference to get quick access to
the functionality.
Menu Tree / Operation Shortcuts ...................................... 9
BUS – UART.......................................................................... 9
BUS – I2C................................................................................ 9
BUS – SPI (4 channel models only) ..................................10
Trigger Bus Menu – I2C......................................................10
Trigger Bus Menu – UART................................................11
Trigger Bus Menu – SPI (4 channel models only)...........11

QUICK REFERENCE
9
Menu Tree / Operation Shortcuts
BUS – UART
BUS – I2C
Define Inputs Include R/W in
address Bus Display
UART
I2C
SPI
On
Off
Event Table
CH1~CH4
SCLK
SCLK
SDA
Select
XXX~XXX
Threshold
Set to TTL 1.4V
Set to ECL -
1.3V
Yes
No
Hex
Binary
Save Event
Table
CH1~CH4
SDA
7 bit
10 bit
Addressing Mode

GDS-3000 Serial Decode User Manual
10
BUS – SPI (4 channel models only)
Trigger Bus Menu – I2C

QUICK REFERENCE
11
Trigger Bus Menu – UART
Trigger Bus Menu – SPI (4 channel models only)

GDS-3000 Serial Decode User Manual
12
MEASUREMENT
Serial Bus........................................................................ 13
Serial Bus Overview.............................................................13
Serial Decode Display..........................................................15
Bus Trigger Settings.............................................................16
Serial Bus Event Tables.......................................................19
UART Serial Bus Interface .................................................20
I2C Serial Bus Interface .......................................................23
SPI Serial Bus Interface.......................................................26

MEASUREMENT
13
Serial Bus
The serial bus trigger and decode software includes support for 3
common serial interfaces: SPI (4 channel models only), UART and
I2C. Each interface is fully configurable to accommodate a wide
range of protocol variation.
Each input can be displayed as binary or hexadecimal. An event
table can also be created to aid in debugging.
Note that the Serial bus trigger and decode software is an optional
extra. An activation key is required to activate the software. For
details, please see page 6.
Serial Bus Overview
UART Universal Asynchronous Receiver Transmitter.
The UART bus is able to accommodate a wide
range of various common UART serial
communications.
The UART serial bus software is suitable for a
number of RS-232 protocol variants.
Inputs Tx, Rx
Threshold Tx, Rx
Configuration Baud rate, Data bits, Parity, Packets,
End of packets, Input polarity
Trigger On Tx Start Bit, Rx Start Bit, Tx End of
Packet, Rx End of Packet, Tx Data,
Rx Data, Tx Parity Error, Rx Parity
Error
I2C Inter Integrated Circuit is a two line serial data
interface with a serial data line (SDA) and serial
clock line (SCLK). The R/W bit can be configured.
Inputs SCLK, SDA
Threshold SCLK, SDA

GDS-3000 Serial Decode User Manual
14
Configuration Addressing mode, Read/Write in
address
Trigger On Start, Repeat Start, Stop, Missing
Ack, Address, Data, Address/Data
SPI The SPI (Serial Interface Peripheral) bus is fully
configurable to accommodate the wide variety of
SPI interfaces. This bus is only available on 4
channel models.
Inputs SCLK, SS, MOSI, MISO
Threshold SCLK, SS, MOSI, MISO
Configuration SCLK edge, SS logic level, Word
size, Bit order
Trigger On SS Active, MOSI, MISO,
MOSI&MISO

MEASUREMENT
15
Serial Decode Display
Start Bit
The Start bit is shown as a green bracket.
Stop Bit
The Stop bit is shown as an orange bracket.
Data Data packets can be shown in Hex or Binary. The
color of the packet is the same as the channel color.
Error Indicator
If there is an error in decoding the serial data, an
error indicator will be shown.
Bus Indicator The Bus indicator shows the bus position. The
active bus is shown with a solid color. The Variable
knob can be used to horizontally position the Bus
indicator when it is active.
Active bus (B1) Activated bus (B1)
Trigger
Configuration
Shows the bus trigger (B1/B2) and the Trigger On
settings.

GDS-3000 Serial Decode User Manual
16
Bus Trigger Settings
The bus trigger conditions should be set at any time after UART,
I2Cor SPI have been selected as the B1 or B2 buses. If the trigger is
not set to Bus the trigger will not be stable.
Panel Operation 1. Press the trigger Menu key and
press Type from the bottom menu.
2. Press Others from the side
menu and select Bus.
3. Press Source Bus from the bottom
menu and select the source bus, B1
or B2. The B1/B2 trigger appear at
the bottom of the display.
From left: Bus, Trigger On.
4. Press Trigger On and select the
triggering condition for the
selected bus.
UART Tx Start Bit, Rx Start Bit, Tx End of
Packet, Rx End of Packet, Tx Data,
Rx Data, Tx Parity Error, Rx Parity
Error
I2C Start, Repeat Start, Stop, Missing
Ack, Address, Data, Address/Data
SPI SS Active, MOSI, MISO,
MOSI&MISO
Trigger On - Data If Data was configured for the Trigger On
setting, then the number of bytes, data and
addressing mode (I2C) can be configured.

MEASUREMENT
17
1. If Trigger On was configured to
Data*, press Data from the bottom
menu.
*The applicable Trigger On settings
are shown below.
UART Tx Data, Rx Data
I2C Data, Address/Data
SPI MOSI, MISO, MOSI&MISO
2. Press Number of Words/Number of
Bytes from the side menu and
choose data length.
UART 1~10 Bytes
I2C 1~5 Bytes
SPI 1~16 Words
3. If I2C is the bus type, press
Addressing Mode to toggle between
7 and 10 bit addressing modes.
4. Press Data (I2C, UART) or
MOSI/MISO (SPI) from the side
menu to edit the triggering data.
To edit the data, use the Variable
knob to highlight a binary or hex
digit and press Select. Use the
Variable knob to choose a value for
the digit and press Select to
confirm.
OR
Binary 0,1,X (don’t care)
Hex 0~F, X (don’t care)

GDS-3000 Serial Decode User Manual
18
Trigger On -
Address
If Address was configured for the Trigger On
setting, then the triggering address/addresses
must be configured.
1. If Trigger On was configured to
Address or Address/Data (I2C), press
Address on the bottom menu.
2. Press Addressing Mode to toggle
between 7 and 10 bit addressing
modes.
3. To choose a preset address as the
default address, press Choose
Preset.
Address Description
0000 000 0 General Call
0000 000 1 START Byte
0000 1XX X Hs-mode
1010 XXX X EEPROM
0000 001 X CBUS
4. Press Apply Preset to set the default
address to the preset.
Note Presets are not available for Trigger On
Address/Data.
5. Press Address from the side menu
to manually edit the triggering
address.
To edit the address, use the

MEASUREMENT
19
Variable knob to highlight a binary
or hex digit and press Select. Use
the Variable knob to choose a value
for the digit and press Select to
confirm.
Binary 0,1, X (don’t care)
Hex 0~F, X (don’t care)
Direction 6. Press Direction on the bottom menu
and choose the direction from the
side menu.
Direction Write, Read, Read or Write
Serial Bus Event Tables
Each serial bus type (UART, I2C, SPI) can have an event table saved
containing each bus event as a .CSV file. An event is defined as the
data on the bus when a Stop or End of Packet (UART) is
encountered. The data associated with each event and the time of
each event is recorded.
File Type Each event table is saved as
Event_TableXXXX.CSV into the designated file
path. Each event table is numbered sequentially
from 0000 to 9999. For example the first event table
will be saved as Event_Table0000.CSV, the second
as Event_Table0001.CSV, and so on.
Event Table Data Each event table saves a timestamp of each event
relative to the trigger as well as the data in each
frame/packet at the time of an event. The
frame/packet data is saved in HEX format.
The table below lists in order the data saved for
each event table.
UART Time, Tx frame data, Rx frame data,
Errors.

GDS-3000 Serial Decode User Manual
20
I2C Time, Repeat Start, Address, Data,
Missing Ack.
SPI Time, MISO frame data, MOSI
frame data.
Example Below shows the data associated with an SPI event
table in a spreadsheet.
Time MOSI MISO
-11.60us 0D87 0D87
-10.16us 06C0 06C0
-8.720us 8343 343
-7.282us 243 243
-5.840us 0C88 0C88
UART Serial Bus Interface
The UART serial bus software is designed to decode RS232 and
other common RS-232 variants such as RS-422, RS-485. The
software configuration is also flexible enough to decode the many
proprietary protocols based on RS-232.
Background Basic RS-232 protocol uses single-ended data
transmissions. The signal voltage levels can be
high (±15V) and employ active low signaling.
High speed variants of RS-232, such as RS-422 and
RS-485 use differential signaling and commonly
employ low voltage differential signals with active
high signaling.
Universal Asynchronous Receiver / Transmitter
(UART) or RS-232 driver/receiver ICs commonly
used for embedded applications typically use
active high signaling with standard IC signal
levels.
Panel operation 1. Insert each of the bus signals (Tx, Rx) to one of
the oscilloscope channels.