Ebyte E180-ZG120B-TB Test Board

Support for Ebyte E180-ZG120B-TB Test Board. More...

Detailed Description

Support for Ebyte E180-ZG120B-TB Test Board.

Overview

Ebyte E180-ZG120B Test Board is equipped with the EFM32 microcontroller. It is specifically designed for low-power applications, having energy-saving peripherals, different energy modes and short wake-up times.

Hardware

MCU

MCU EFR32MG1B232F256GM32
Family ARM Cortex-M4F
Vendor Ebyte
Vendor Family EFM32 Mighty Gecko 1B
RAM 32.0 KiB (1.0 KiB reserved by radio blob)
Flash 256.0 KiB
EEPROM no
Frequency up to 38.4 MHz
FPU yes
MPU yes
DMA 8 channels
Timers 2x 16-bit + 1x 16-bit (low power)
ADCs 12-bit ADC
UARTs 2x USART, 1x LEUART
SPIs 2x USART
I2Cs 1x
Vcc 1.85 V - 3.8 V
Datasheet Datasheet
Manual Manual
Board Manual Board Manual

Peripheral mapping

Peripheral Number Hardware Pins Comments
ADC 0 ADC0 CHAN0: internal temperature Ports are fixed, 14/16-bit resolution not supported
HWCRYPTO AES128/AES256, SHA1, SHA256
RTT RTCC 1 Hz interval. Either RTT or RTC (see below)
RTC RTCC 1 Hz interval. Either RTC or RTT (see below)
Timer 0 TIMER0 + TIMER1 TIMER0 is used as prescaler (must be adjecent)
1 LETIMER0
UART 0 USART0 RX: PA1, TX: PA0 Default STDIO output

User interface

Peripheral Mapped to Pin Comments
Button PB0_PIN PD15 Mode Change
PB1_PIN PD13 Touch Link
PB2_PIN PB11 Baud Rate Reset
LED LED0_PIN PF2 GPIO2 LED
LED1_PIN PF3 Link LED

The fourth button with the Chinese description is the reset button.

Implementation Status

Device ID Supported Comments
MCU EFR32MG1B yes Power modes supported
Low-level driver ADC yes
Flash yes
GPIO yes Interrupts are shared across pins (see reference manual)
HW Crypto yes
I2C yes
PWM yes
RTCC yes As RTT or RTC
SPI partially Only master mode
Timer yes
UART yes USART is shared with SPI. LEUART baud rate limited (see below)
USB no

Board configuration

Clock selection

There are several clock sources that are available for the different peripherals. You are advised to read AN0004.0 to get familiar with the different clocks.

Source Internal Speed Comments
HFRCO Yes 19 MHz Enabled during startup, changeable
HFXO No 38.4 MHz
LFRCO Yes 32.768 kHz
LFXO No 32.768 kHz
ULFRCO No 1 kHz Not very reliable as a time source

The sources can be used to clock following branches:

Branch Sources Comments
HF HFRCO, HFXO Core, peripherals
LFA LFRCO, LFXO Low-power timers
LFB LFRCO, LFXO, CORELEDIV2 Low-power UART
LFE LFRCO, LFXO Real-time Clock and Calendar

CORELEDIV2 is a source that depends on the clock source that powers the core. It is divided by 2 or 4 to not exceed maximum clock frequencies (EMLIB takes care of this).

The frequencies mentioned in the tables above are specific for this starter kit.

It is important that the clock speeds are known to the code, for proper calculations of speeds and baud rates. If the HFXO or LFXO are different from the speeds above, ensure to pass EFM32_HFXO_FREQ=freq_in_hz and EFM32_LFXO_FREQ=freq_in_hz to your compiler.

You can override the branch's clock source by adding CLOCK_LFA=source to your compiler defines, e.g. CLOCK_LFA=cmuSelect_LFRCO.

Low-power peripherals

The low-power UART is capable of providing an UART peripheral using a low-speed clock. When the LFB clock source is the LFRCO or LFXO, it can still be used in EM2. However, this limits the baud rate to 9600 baud. If a higher baud rate is desired, set the clock source to CORELEDIV2.

Note:** peripheral mappings in your board definitions will not be affected by this setting. Ensure you do not refer to any low-power peripherals.

RTC or RTT

RIOT-OS has support for Real-Time Tickers and Real-Time Clocks.

However, this board MCU family has support for a 32-bit Real-Time Clock and Calendar, which can be configured in ticker mode or calendar mode. Therefore, only one of both peripherals can be enabled at the same time.

Configured at 1 Hz interval, the RTCC will overflow each 136 years.

Hardware crypto

This MCU is equipped with a hardware-accelerated crypto peripheral that can speed up AES128, AES256, SHA1, SHA256 and several other cryptographic computations.

A peripheral driver interface is proposed, but not yet implemented.

Usage of EMLIB

This port makes uses of EMLIB by Ebyte to abstract peripheral registers. While some overhead is to be expected, it ensures proper setup of devices, provides chip errata and simplifies development. The exact overhead depends on the application and peripheral usage, but the largest overhead is expected during peripheral setup. A lot of read/write/get/set methods are implemented as inline methods or macros (which have no overhead).

Another advantage of EMLIB are the included assertions. These assertions ensure that peripherals are used properly. To enable this, pass DEBUG_EFM to your compiler.

Pin locations

The EFM32 platform supports peripherals to be mapped to different pins (predefined locations). The definitions in periph_conf.h mostly consist of a location number and the actual pins. The actual pins are required to configure the pins via GPIO driver, while the location is used to map the peripheral to these pins.

In other words, these definitions must match. Refer to the data sheet for more information.

This MCU has extended pin mapping support. Each pin of a peripheral can be connected separately to one of the predefined pins for that peripheral.

Flashing the device

To flash, SEGGER JLink is required.

Flashing is supported by RIOT-OS using the command below:

make flash

To run the GDB debugger, use the command:

make debug

Or, to connect with your own debugger:

make debug-server

Some boards have (limited) support for emulation, which can be started with:

make emulate

Supported Toolchains

For using the Ebyte E180-ZG120B-TB starter kit we strongly recommend the usage of the GNU Tools for ARM Embedded Processors toolchain.

License information

Ebyte' EMLIB: zlib-style license (permits distribution of source).

Files

file  board.h
 Board specific definitions for the E180-ZG120B-TB starter kit.
 
file  gpio_params.h
 Board specific configuration of direct mapped GPIOs.
 
file  periph_conf.h
 Configuration of CPU peripherals for the E180-ZG120B-TB Test Board.