GigaDevice Semiconductor GD32 Series Installation and operating instructions

GigaDevice Semiconductor Inc.
GD32 MCU Power Consumption
Testing Process
Application Note
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Table of Contents
Table of Contents ...........................................................................................................1
List of Figures ................................................................................................................2
List of Tables ..................................................................................................................3
1. Introduction..............................................................................................................4
2. Power consumption testing process.....................................................................5
2.1. Preparation of test tools .............................................................................................................. 5
2.2. Power consumption testing setting ........................................................................................... 5
2.3. Testing process ............................................................................................................................ 6
2.4. General Problems......................................................................................................................... 7
2.5. Case description .......................................................................................................................... 8
3. Summary ..................................................................................................................9
4. Revision history.....................................................................................................10

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List of Figures
Figure 2-1. Schematic diagram of hardware connection for test.................................................... 6
Figure 2-2. Hardware cable connections for Battery supply test ................................................... 7
Figure 2-3. Power consumption characteristic................................................................................. 8

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List of Tables
Table 4-1. Revision history ............................................................................................................... 10

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1. Introduction
This article is designed for GD32 MCU, mainly introduces the power testing process, including
the selection and use of test instrument specifications, hardware circuit design, software code
use, test data recording, so as to achieve accurate power data.

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2. Power consumption testing process
2.1. Preparation of test tools
MCU power consumption testing generally requires the following tools:
1. MCU chip to be tested. In general, at least three samples of the same batch and process
of MCU should be taken as the tested objects. After getting the chip, check whether the silk
screen is clear on the surface of the chip package, and the pin is clean and has no sign of
bending damage.
2. Minimum system board, only the power supply, crystal input pin, reset, download port,
BOOT pin, to avoid the influence of external excess circuit current consumption.
3. Multimeter used to measure the input current of the MCU under test. A multimeter with at
least four and a half digits should be used. If possible, a multimeter with a higher digit should
be used to ensure accurate and reliable test data. During the test, connect the pen of the
multimeter in the way of current measurement and set the gear to DC current.
4. Signal source used to provide an external active clock for the MCU under test under some
test requirements. The recommended signal source is an instrument with a frequency of
30MHz, a resolution of 16 bits, and a sampling rate of 250MSa / s or higher.
5. Dc digital power supply, according to test requirements to adjust the output use.
6. J-Link, use to test code download.
2.2. Power consumption testing setting
Hardware configuration
According to the comprehensive consideration of user performance and power consumption,
refer to the chapter of clock tree in user manual and power consumption with datasheet, select
the appropriate power supply voltage and crystal oscillator input, and configure the clock
source as the required master frequency by operating the frequency divider and frequency
multiplier to set the clock source to the desired primary frequency.
Select an appropriate stabilizing voltage source according to the specific product, and adjust
the voltage value to 3.3V / 5V. Most of the products use 3.3V power supply, some of the car
gauge chips use 5V power supply compatible with 3.3V. The crystal oscillator input supports
passive crystal oscillator and active crystal oscillator. Select the appropriate crystal oscillator
by referring to the crystal oscillator input range specified in the clock tree of the user manual
of the chip. When the external crystal does not meet the test conditions, the signal source can
be used as the HXTAL input to facilitate the test, and the MCU enables BYPASS MODE.
Signal source output requirements: high resistance output, square wave, duty cycle 50%,

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frequency 4MHz / 2MHz, VPP=3.3V, OFFSET=1.65V.
Software configuration
Peripheral enabled / disabled. The software developer turns on / off the relevant peripheral
clock by manipulating library functions in the code according to the user manual.
I / O port configuration. Before entering low power mode, all spare I / O pins need to be
configured as analog inputs. It should be noted that the minimum package is configured as
the maximum package pins, even if these pins are not drawn in the package. Before
configuring pins, you are advised to add a wait time to the code to prevent the debugging port
from being disabled.
Low power mode selection. Select the required low power mode according to the
configuration code in the power consumption section of the datasheet. After entering the low
power mode, the power consumption is close to that of the datasheet.
2.3. Testing process
The hardware and software test conditions of each mode are different. After understanding
the basic requirements of each mode, you can perform the test in the following sequence to
simplify the process, save time and cost, and reduce the loss of hardware insertion and
removal.
Build hardware framework
Select appropriate power supply, external crystal / signal source, and configure BOOT pins to
form the MCU minimum system. The actual power consumption of "IVDD+IVDDA" under different
power consumption modes can be tested by connecting the ammeter in series in the minimum
system of power supply and MCU according to the power consumption section of the
datasheet, as shown in Figure 2-1. Schematic diagram of hardware connection for test.
Figure 2-1. Schematic diagram of hardware connection for test
MCU minimum
system
VDD
VDDA
mA
GND
VOUT GND
+ -
Power
supply
As shown in Figure 2-2. Hardware cable connections for Battery supply test, when MCU
VDD is disconnected, its VBAT pin can be connected to backup source power supply such as
battery or other power supply. MCU Battery supply has four modes: LXTAL High driving,
LXTAL Medium High driving, LXTAL Medium Low driving, LXTAL Low driving. The test is to

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separately test the input current of the VBAT pin in each mode of Battery supply when the
MCU VDD is disconnected. Generally, the common VBAT supply voltage is 3.6V, 3.3V, 2.6V,
1.8V. According to the four modes, it is divided into four codes. Each code is directly compiled
and downloaded, and tested and recorded by changing different power supply voltages.
Figure 2-2. Hardware cable connections for Battery supply test
MCU minimum
system
VDD
VDDA
mA
GND
VOUT GND
+ -
Power
supply
VBAT
Download code
The test is generally configured by the software writer, and the code is written according to
the requirements of the corresponding power mode in the data manual. If there are special
values of clock frequency and power supply voltage, the test conditions need to be set
separately. Download the code into MCU.
Power consumption reading
Separate the minimum system board from the debugging tool. Turn off and restart the power
supply to generate a power-on reset and disable the internal debug circuit. Test the
corresponding power consumption and wait for the ammeter to stabilize before recording data.
2.4. General Problems
Code download exception
"No Cortex-M SW Device Found" is displayed. Check whether all the connections are correct
and whether there is bad contact; Check that the download port is configured to Analog input.
If the first download is normal and the second download is abnormal, check whether the
system clock Settings and waiting time are correct. If the Settings are not correct, the
download port will be configured as an analog input mode after the program is downloaded
for the first time, making the MCU no longer recognized and unable to perform subsequent
downloads. At this point, we need to put MCU into ISP mode and erase flash. Reset the code
and download.
The message "Cannot Load Flash Device Description" is displayed. Check whether the
Options for Target of Keil has installed the PACK package and whether the MCU model is
selected; All wiring is correct, there is no forget jumper, poor contact and other situations.
The message "Cannot Load Flash Programing Algorithm" is displayed. Whether the correct

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Flash Size is added to Programing Algorithm in the Debug-Flash Download and whether the
RAM for Algorithm is set correctly.
Data deviation
Each test will have a reference value. When the measurement contrast deviation is large, the
following checks can be done: Check whether the hardware test system is connected to other
wire paths, resulting in system leakage; It is necessary to identify the source of reference
values to determine whether power consumption differences are caused by power
consumption reduction or function adjustment and improvement. Determine if the code is
written to meet the power test requirements, such as whether the GPIO is configured to
analog input state, whether all peripherals are enabled or disabled, whether the register is
configured successfully, and whether the system clock is configured correctly; Check whether
the system clock is set correctly. You can first check whether the code parameters are
correctly configured, and then use PA8 to output the system clock and use oscilloscope to
observe the running clock frequency.
2.5. Case description
Take GD32F303 series as an example, as shown in Figure 2-3. Power consumption
characteristic. power consumption characteristics are configured according to the test
conditions in the datasheet. Under Deepsleep mode, MCU is selected to supply 3.3V power,
external crystal oscillator is selected as 8MHz passive crystal oscillator, system clock is set
as 120MHz, and LDO is set in lower power mode. Turn off IRC40K, turn off RTC, and
configure all GPIOs in analog input mode. At 25°C, the Deepsleep mode power range of the
minimum system on the chip should be between 159.8uA and 1100uA.
Figure 2-3. Power consumption characteristic

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3. Summary
According to the measured application time and current consumption of each MCU mode, the
average current consumption can be estimated in the actual application program, so that
users can calculate the sustainable working time of MCU under the condition of battery power.
In general, the test result under the standard testing process is close to the value of the
datasheet, but considering the individual difference of the chip and the update of the chip
version, the actual data may be inconsistent with the datasheet.

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4. Revision history
Table 4-1. Revision history
Revision No.
Description
Date
1.0
Initial Release
Apr.7, 2023

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