KeyStone 1 UART Self Test Kit
March 2015
KeyStone 1
UART Self Test Kit
User’s Guide
Revision history
Version Date Author Description of Change
1.0 December 16, 2013 Vincent Han Initial release
1.1 March 20, 2015 Brighton Feng 1. Print device information including device type, speed
grade, boot mode, required voltage, ID…
2. to support selective interrupt enable for different case in
KeyStone_UART_Interrupts_Init().
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KeyStone UART Self Test Kit User’s Guide
Contents
1 Overview............................................................................................................................................. 3
2 Test Methods and test cases............................................................................................................4
2.1 UART Loopback & Throughput Test.........................................................................................4
2.2 UART Transmit Increasing Sequence Test...............................................................................5
2.3 UART Transmit Continuous Data Pattern Test..........................................................................5
2.4 UART Interact with PC Test......................................................................................................5
2.5 Test with different masters........................................................................................................6
2.6 UART Baud Rate Configuration Accuracy.................................................................................6
3 Test Project........................................................................................................................................ 7
3.1 CCS Project.............................................................................................................................. 7
3.2 Hardware Connections and Drivers Preparation.......................................................................8
3.3 To Run the Test Program on KeyStone EVM..........................................................................12
3.4 Test Configurations.................................................................................................................13
3.5 Migrate the Project to Customs’ Boards..................................................................................14
References.......................................................................................................................................... 14
Appendix: Typical test output............................................................................................................15
Figures
Tables
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KeyStone UART Self Test Kit User’s Guide
1 Overview
Figure 1 shows the KeyStone UART functional diagram.
Figure 1. KeyStone UART functional diagram
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KeyStone UART Self Test Kit User’s Guide
Some of KeyStone devices have 2 UART modules while some devices have only 1 UART
module, for devices have 2 UART, the 2 modules can work separately as 2 functional units. The
major features supported by UART in KeyStone are:
1 START bit + data bits (5, 6, 7, 8) + 1 PARITY bit (optional) + STOP bit (1, 1.5, 2) for UART
transmitting format.
1 START bit + data bits (5, 6, 7, 8) + 1 PARITY bit (optional) + 1 STOP bit for UART
receiving format.
Configurable baud rate.
The receiver and transmitter FIFOs store up to 16 bytes.
Refer to “KeyStone_1_Self_Test_Kit_User's_Guide(READ ME FIRST).doc” for some common
information about K1 STK.
2 Test Methods and test cases
Several test methods are used to cover multiple usages cases.
2.1 UART Loopback & Throughput Test
Two loopback tests are implemented: internal loopback and external line loopback.
Figure 2. UART internal loopback
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KeyStone UART Self Test Kit User’s Guide
Figure 3. UART external line loopback
The purpose of the internal loopback test is mainly to check the KeyStone SOC itself; the
purpose of the external line loopback test is mainly to check the components and connections
for UART on the board.
If the internal loopback test fails, the problem should be in the KeyStone SOC, you may need to
check the clock, power or configurations for the SOC; if the internal loopback test passes while
the external line loopback test fails, then the problem is on the other components or connection
on the board.
The throughput is also measured in loopback test to provide the basic benchmark of the
throughput in different baud rate configurations, ranging from 115200 to 3686400 bps (double
the rate for each test iteration).
2.2 UART Transmit Increasing Sequence Test
The purpose of this test method is mainly to check the UART configurations in Tx side, by
outputting increasing sequence to PC terminal, it’s easy to check whether the UART
configuration is correct or not.
The ASCII code value of the increasing sequence is from 0 – 127 which covers the alphabet,
number and daily used punctuations in ASCII, by checking the output on PC terminal, we can
basically know whether the UART configuration is correct or not.
2.3 UART Transmit Continuous Data Pattern Test
The purpose of this test method is mainly to generate waveform on TX pin to make it easy for
hardware signal checking with oscilloscope. We can use the continuous data pattern such as
0x55 or 0xAA to output square wave, and then check the signal from the hardware circuit to
check the signal quality or the hardware connections.
2.4 UART Interact with PC Test
The purpose of this test method is mainly to check both of the Tx and Rx sides on hardware. For
Tx side, the data sent by UART will be received and printed on PC terminal. For Rx side, the
data received from PC will be retransmitted from UART back to PC which will show the echo of
the keyboard input.
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