Model B Evaluation Board

Overview

The RTL87x2G model B evaluation board is compatible with the following daughter boards:
- RTL8772GWP Daughter Board
- RTL8772GWF Daughter Board
The RTL87x2G model B evaluation board provides a hardware environment for user development, including:
- 5V to 3.3V & 1.8V power module
- Support QSPI (Group1), I8080 (Group2), RGB888 display interface
- Support audio module (AMIC, DMIC, AEC) interface
- Support Wi-Fi module and SD Nand Flash module interface
- Support RS485 and A2C interface
- Support infrared sensing interface
- Support temperature and humidity sensor interface
- Ethernet module
- USB to UART chip, FT232RL

Note

If you require modules for the model B evaluation board, please contact Realtek FAE for assistance.

Blocks Distribution

Blocks distribution on the front and back of the model B evaluation board are as following.

../../../_images/EVB_model_B_blocks_distribution_Diagram-Back.png — Model B EVB blocks distribution diagram-Back

The following introduces the blocks on the evaluation board in counterclockwise order.

Introduction of the blocks on the model B evaluation board
Blocks	Introductionm
Display Interface Type Selection	Model B EVB supports QSPI (Group1), I8080 (Group2), RGB888 display interface
A2C Interface	Used to connect the A2C module
RS485 Interface	Used to connect the RS485 module
Infrared Sensing Interface	Used to connect the infrared sensor module
SWD Interface	Used to SWD debug
Reset Key	Pressing this key resets the system
UART/LOG Test Interface	Supports download mode and normal mode
Display Power Selection	Supports USB port CON1 or CON2 to power the display
USB Port CON1	Used to power EVB and communicate with RTL87x2G via USB
External Power Supply	Provides external power supply of 1.8V and 3.3V
IC Power Voltage Selection	Provides IC power voltage options of 1.8V or 3.3V
Audio Analog-to-digital Conversion Interface	Used to connect the audio analog-to-digital conversion module
Wi-Fi and SD Nand Flash Multiplexed Interface	Used to connect Wi-Fi module or RTK SD Nand Flash daughter board
DMIC Interface	Used to connect the external DMIC daughter board
AMIC Interface	Used to connect the external AMIC daughter board
Microphone and Headphone Sockets	Supports 3.5mm audio interface
Ethernet Module	The Ethernet module adopts RTL8201FR and supports RMII interface
Temperature and Humidity Sensor Interface	Used to connect to the temperature and humidity sensor
24bits ADC Interface	24bits ADC, AIN0-3 can be used as four single-ended inputs. AIN0-1 and AIN2-3 can be used as two differential inputs
EVB Daughter Board Socket	Used to connect the EVB daughter board with an anti-reverse insertion mechanism
USB Port CON2	Used to power the EVB and connect USB to UART chip FT232RL for downloading programs or debug
Display Socket	Used to connect display screen

Interfaces Distribution

Note

Pin names on the evaluation board preceded by a forward slash, such as /P1_7 or /P3_7, indicate that these pins are not directly connected to the IC. When using these pins, you will need to place a corresponding 0-ohm resistor.

Blocks and Interfaces Introduction

EVB Daughter Board

Daughter board can be removed and replaced. There is an anti-reverse insertion mechanism between mother board and daughter board. RTL8762GWP/GWF daughter boards are compatible with the RTL87x2G model B evaluation board.

../../../_images/RTL8772GWP_and_RTL8772GWF_Daughterboard.png — RTL8772GWP and RTL8772GWF Daughterboard

Power

USB Port CON1: USB port CON1 is used to power the model B evaluation board and communicate with RTL87x2G via USB.

USB Port CON2: USB port CON2 is used to power the model B evaluation board and connect USB to UART chip FT232RL for downloading programs or debug.

../../../_images/USB_socket_CON1_2_of_EVB_model_B.png — USB port CON1 and CON2 of model B EVB

IC Power Voltage Selection: VDD_VBAT/VDDIO/VDDIO_EXT can choose 1.8V or 3.3V power supply according to the actual application, with default connection of 3.3V. Power input pins are introduced as follows:

Introduction of power supply input pins on model B EVB
Pin Name	Function
V33_USB	Power supply for USB transceiver
VD33_PA	Power supply for the internal +14dBm radio power amplifier
AVDD	Power supply for the internal 24bits ADC
VDD_VBAT	Power supply for the internal regulator and analog circuitry
VDDIO	Power supply for PAD and Flash
VDDIO18	Power supply for MCM PSRAM
VDDIO_EXT	Power supply for external devices

Note

VDDIO and VDDIO_EXT power supply should be consistent.
When using RTL8772GWP daughter board, VDDIO18 can only select 1.8V.

../../../_images/Power_select_of_EVB_model_B.jpg — IC Power select connecting of model B EVB

EVB Interfaces

UART/LOG Test Interface

Download mode: Both button switches marked in red need to be pressed, which will pull down the LOG pin, then press reset button or power on again to enter download mode.

Normal mode: Both button switches marked in red need to be released. Press reset button or power on again to start running the program. Log pin can be used for debug.

../../../_images/UART_LOG_communication_switches_of_EVB_model_B.png — UART/LOG communication switches of model B EVB

RS485 Interface: When using RS485, it is necessary to connect the three sets of pins marked in the blue box with jumpers. The RS485 module input is 3.3V-TTL. When connecting the RS485 module to EVB, pay attention to the one-to-one correspondence between each pin on the module and the RS485 interface on the EVB to prevent reverse insertion.

../../../_images/RS485_interface_module_of_EVB_model_B.jpg — RS485 interface module of model B EVB

../../../_images/RS485_module_connecting_of_EVB_model_B.jpg — RS485 module connecting of model B EVB

A2C Interface: A2C interface is shown in the green box, where there are two rows of green boxes that can be as A2C interface, and the other row is the A2C test interface. When using CAN module, it is necessary to connect the three sets of pins marked in the blue box with jumpers. The module adopts TJA1051, which is a high-speed transceiver that provides differential transmission and reception functions for the controller, with a transmission rate of up to 1Mbit/s. When connecting the module to EVB, pay attention to the one-to-one correspondence between each pin on the module and the A2C interface on the EVB to prevent reverse insertion.

../../../_images/CAN_interface_and_module_of_EVB_model_B.jpg — A2C interface and module of model B EVB

../../../_images/CAN_module_connecting_of_EVB_model_B.jpg — A2C interface connecting of model B EVB

Audio Analog-to-digital Conversion Interface: MIC_L and MIC_R in audio analog-to-digital conversion interface are connected to microphones as audio input; The audio analog-to-digital conversion module is placed in U19. Pay attention to the pin order when connecting to prevent reverse connection. Audio analog-to-digital conversion module uses a PCM1808 device with a 24bits A/D converter, and includes a digital decimation filter and a high pass filter to eliminate the DC part of the input signal. PCM1808 supports master-slave mode and two data formats in the serial audio interface. It supports power down and reset functions by pausing the system clock, with a sampling rate range of 8kHz~96kHz. The power supply is 5V analog power supply and 3.3V digital power supply.

../../../_images/Audio_stereo_analog-to-digital_conversion_module_interface_of_EVB_model_B.jpg — Audio analog-to-digital conversion interface of model B EVB

../../../_images/MicrophoneL_and_audio_stereo_analog-to-digital_conversion_moduleR_of_EVB_model_B.jpg — Microphone(L) and audio analog-to-digital conversion module(R)

../../../_images/audio_stereo_analog-to-digital_conversion_module_connecting_of_EVB_model_B.jpg — Audio analog-to-digital conversion module connecting of model B EVB

Infrared Sensing Interface: When using infrared sensor module, it is necessary to place a jumper on J127, and then plug the infrared sensing module into J77. Pay attention to the order of the plug positions to prevent reverse connection. The infrared sensor module adopts HC-SR505, with a working voltage range of 4.5~20V and a static current of less than 50uA. When a person enters its sensing range, it will output a high level, and when leaves the sensing range, it will automatically delay closing the high level and output a low level. Support for repeatable triggering, that is, after outputting a high level, if a person is active within its sensing range within a delay time, its output will remain high until the person leaves, and the delay will change the high level to low level.

../../../_images/Infrared_sensing_interface_of_EVB_model_B.jpg — Infrared sensing interface of model B EVB

../../../_images/Infrared_sensing_module_connecting_of_EVB_model_B.jpg — Infrared sensor module connecting of model B EVB

Temperature and Humidity Sensor Interface: The temperature and humidity sensor module has a power supply voltage of 2.4~5.5V and supports the I2C communication protocol. The temperature range and accuracy are -40~+125℃ and ±0.2℃, respectively. The humidity range and accuracy are 0~100% RH and ± 2% RH, respectively. The power consumption is 4.8uW (once/second). When connecting, pay attention to the sequence of plug positions to prevent reverse connections.

../../../_images/Temperature_and_humidity_sensor_interface_of_EVB_model_B.jpg — Temperature and humidity sensor interface of model B EVB

../../../_images/Temperature_and_humidity_sensor_connecting_of_EVB_model_B.jpg — Temperature and humidity sensor connecting of model B EVB

Wi-Fi and SD Nand Flash Multiplexed Interface

The Wi-Fi module is BL-M8189FS6, supporting SDIO interfaces. Supports the IEEE 802.11b/g/n standard and provides a PHY rate of up to 150 Mbps, providing rich wireless connectivity and reliable throughput over long distances.

../../../_images/WiFi_interface_and_module_of_EVB_model_B.jpg — Wi-Fi interface and module of model B EVB

SD NAND flash interface can be used with the RTK SD NAND flash daughterboard. When connecting, insert the SD NAND flash interface marked in the blue box on the right of figure, paying attention to the order of the connection positions to prevent reverse connection.

../../../_images/SD_NAND_flash_interface_and_daughterboard_of_EVB_model_B.jpg — SD NAND flash interface and daughterboard of model B EVB

../../../_images/SD_NAND_flash_connection_of_EVB_model_B.jpg — SD NAND flash connection of model B EVB

Note

Normal Mode: When using the Wi-Fi or SD Nand Flash module, you need to use a jumper to connect the J35.
Low Power Mode: Remove the jumper from J35, and then connect the pin headers marked in the blue box in J37 to any GPIO. When the GPIO output is high, the Wi-Fi or SD Nand Flash modules work normally. When the GPIO output is low, the modules do not work.

Ethernet Module: The ethernet module uses RTL8201FR, supports RMII interface. The button marked in the red box is the reset button for the Ethernet module.

../../../_images/Ethernet_module_of_EVB_model_B.jpg — Ethernet module of model B EVB

EVB Pin Assignment

Please refer to the latest RTL87x2G IOPin Information table about the pin assignment of EVB.

EVB User Guide

EVB Power Connection

Model B EVB can be powered independently using USB port CON2, in which case the USB communication function of RTL87x2G cannot be used, but programs can be normally downloaded into RTL87x2G. The power connection of the evaluation board is shown below. All jumpers marked in the red box need to be connected.

../../../_images/Power_supply_with_USB_socket_CON2_of_EVB_model_B.png — Power supply with USB port CON2 of model B EVB

If the USB communication function of RTL87x2G needs to be used, both the USB ports CON1 and CON2 on the evaluation board need to be connected. In this situation, the power supply connection is shown below, and all jumpers marked in the red box need to be placed. The difference between using a single USB port CON2 for power supply is that in J120, the jumper is selected as 5V_IC.

../../../_images/Power_supply_with_USB_socket_CON1_2_of_EVB_model_B.png — Power supply with USB port CON1 and CON2 of model B EVB

Download Mode Connection

P0_3 is the download mode selection pin. When P0_3 is pulled low, hardware reset or power cycling will put the system into download mode. In the UART/LOG test interface, both switches marked in the red box need to be pressed, which will pull P0_3 (log) low, connect P3_0 to RX and P3_1 to TX. Then press the reset button or power cycle the system to enter download mode.

Normal mode connection

Please confirm that the two button switches marked in the red box in the UART/LOG test interface are released, which means that P0_3 (log) is connected to RX, P3_0 and P3_1 are disconnected from RX and TX respectively. Use the Debug Analyzer via the USB port CON2 for debug.

Ethernet and SDIO Interface Switching

Due to the fact that the Ethernet module, SDIO and Wi-Fi module share the same set of SDIO interfaces. When using the Ethernet module, it is necessary to place the resistors in switch to Ethernet interface and remove the resistors in switch to SDIO interface; When using the Wi-Fi or SDIO module, it is necessary to place the resistors in switch to SDIO interface and remove the resistors in switch to Ethernet interface. By default, the Ethernet module is selected.

../../../_images/Switch_to_Ethernet_interface_of_EVB_model_B.jpg — Switch to Ethernet interface of model B EVB

../../../_images/Switch_to_SDIO_interface_of_EVB_model_B.jpg — Switch to SDIO interface of model B EVB

Display Interface

Power Selection: When using USB port CON2 for power supply, 5VDIS can only connect to 5V_FT. When using USB port CON1 and CON2 for power supply, 5VDIS can be connected to 5V_FT or 5V_IC.

../../../_images/Single_USB_cable_power_supply_and_burning_mode_5VDIS_connecting_to_5V_FT.png — Single USB cable power supply and burning mode, 5VDIS connecting to 5V_FT

../../../_images/Dual_wire_burning_debugging_5VDIS_connecting_to_5V_IC.png — Dual wire burning debugging, 5VDIS connecting to 5V_FT or 5V_IC

Display Interface Type Selection: Display type interface can be selected by setting the status of LCD_IM[1:0] based on used screen. Please refer to the datasheet of display driver chip for details.

Pin assignment of the QSPI (Group1), I8080 (Group2), RGB888 interface of model B evaluation board
PIN Name	QSPI (Group1) Interface	I8080 (Group2) Interface	RGB888 Interface
P2_2	TP_RST	TP_RST	TP_RST
P2_3	TP_INT	TP_INT	TP_INT
P2_4	TP_SCL	TP_SCL	TP_SCL
P2_5	TP_SDA	TP_SDA	TP_SDA
P1_4	LCD_BL_CTRL	LCD_BL_CTRL	LCD_BL_CTRL
P4_3	QSPI_CS	8080_D7	D7
P3_4	QSPI_DCX		D16
P4_0	QSPI_CLK (PHY)	8080_D4	D4
P3_3	QSPI_SIO3		D15
P3_2	QSPI_SIO2		D14
P4_1	QSPI_SIO1	8080_D5	D5
P4_2	QSPI_SIO0	8080_D6	D6
P3_6	LCD_RESX	LCD_RESX	CM
P0_5	LCD_TE (VSYNC)	8080_D1	D1
P0_2		8080_WR#	PCLK
P1_5		8080_DCX	HSYNC
P1_6		8080_RD#	SD
P0_7		8080_D3	D3
P0_6		8080_D2	D2
P0_4		8080_D0	D0
P0_1		8080_LCD_TE	VSYNC
P0_0		8080_CS#	DE
P5_0			D23
P5_1			D22
P5_2			D21
P5_3			D20
P5_4			D19
P5_5			D18
P3_5			D17
P9_2			D13
P4_7			D12
P4_6			D11
P4_5			D10
P4_4			D9
P1_2			D8
P9_1			SPI_CS
P9_0			SPI_CLK
P1_3			SPI_DO

IC Power Consumption Test

Model B evaluation board provides IC power consumption test interface for 1.8V and 3.3V.

When the IC is powered by 3.3V, disconnect J135 before measuring. Then connect the ammeter to measure the current passing through J135.
When the IC is powered by 1.8V, disconnect J136 before measuring. Then connect the ammeter to measure the current passing through J136.

../../../_images/Schematic_Diagram_of_power_consumption_points_on_EVB_model_B.jpg — IC power consumption test interface

Note

Please properly connect the jumpers according to the introduction of power supply input pins and the power consumption measurement scenarios.
To avoid extra power consumption, it is necessary to turn off log printing.
To avoid the effect from debugging equipment, please do not connect UART, SWD, and debugger.
To avoid the effect of the Ethernet module, remove resistors R47, R49, and R266, or configure P1_7, P9_3, and P9_4 to pull-none and shutdown mode.
When using an external DC power supply, the jumpers of J135 and J136 need to be unplugged, then DC power needs to be connected to VDD_3V3_IC. Note that when using RTL8772GWP daughter board, because MCMPSRAM of RTL8772GWP daughter board is powered by 1.8V, the voltage of the DC power source connected to VDD_1V8_IC can only be 1.8V.

RF Test

When performing RF performance testing for Bluetooth/Zigbee using the RF Test Tool, both buttons marked in red need to be pressed down. Then, remove the jumper from the log key, allowing P0_3 to return to a floating state, P3_0 connected to RX, and P3_1 connected to TX.