ARM V2M MPS2 Armv6-m (AN383)
Overview
Currently mps2/an383 is the only mps2 Armv6-m based board target supported in Zephyr.
It provides support for the ARM Cortex-M0+ (AN383) CPU and the following devices:
- Nested Vectored Interrupt Controller (NVIC) 
- System Tick System Clock (SYSTICK) 
- Cortex-M System Design Kit UART 
 
In addition to enabling actual hardware usage, this board target can also use FVP. to emulate the AN383 platform running on the MPS2+.
More information about the board can be found at the V2M MPS2 Website.
The Application Note AN383 can be found at Application Note AN383.
Note
This board target makes no claims about its suitability for use with actual MPS2 hardware systems using AN383, or any other hardware system. It has been tested on FVP.
Hardware
ARM V2M MPS2 AN383 provides the following hardware components:
- ARM Cortex-M0+ 
- ARM IoT Subsystem for Cortex-M 
- Form factor: 140x120cm 
- ZBTSRAM: 8MB single cycle SRAM, 16MB PSRAM 
- Video: QSVGA touch screen panel, 4bit RGB VGA connector 
- Audio: Audio Codec 
- Debug: - ARM JTAG20 connector 
- ARM parallel trace connector (MICTOR38) 
- 20 pin Cortex debug connector 
- 10 pin Cortex debug connector 
- ILA connector for FPGA debug 
 
- Expansion - GPIO 
- SPI 
 
Note
4 MB of flash memory (in ZBTSRAM 1, starting at address 0x00400000) and 4 MB of RAM (in ZBTSRAM 2 & 3, starting at address 0x20000000) are available.
Supported Features
The mps2/an383 board target supports the following hardware features:
| Interface | Controller | Driver/Component | 
|---|---|---|
| NVIC | on-chip | nested vector interrupt controller | 
| SYSTICK | on-chip | systick | 
| UART | on-chip | serial port-polling; serial port-interrupt | 
| GPIO | on-chip | gpio | 
| WATCHDOG | on-chip | watchdog | 
| TIMER | on-chip | counter | 
| DUALTIMER | on-chip | counter | 
Other hardware features are not currently supported by the port. See the V2M MPS2 Website for a complete list of V2M MPS2 board hardware features.
The default configuration can be found in boards/arm/mps2/mps2_an383_defconfig
Interrupt Controller
MPS2 is a Cortex-M0+ based SoC and has 6 fixed exceptions and 32 IRQs.
A Cortex-M0+ board uses vectored exceptions. This means each exception calls a handler directly from the vector table.
Handlers are provided for exceptions 1-3, 11, and 14-15. The table here MPS2 is a Cortex-M0+ based SoC and has 15 fixed exceptions and 45 IRQs.
| Exc# | Name | Remarks | Used by Zephyr Kernel | 
|---|---|---|---|
| 1 | Reset | system initialization | |
| 2 | NMI | system fatal error | |
| 3 | Hard fault | system fatal error | |
| 11 | SVC | system calls, kernel run-time exceptions, and IRQ offloading | |
| 14 | PendSV | context switch | |
| 15 | SYSTICK | optional | system clock | 
Pin Mapping
The ARM V2M MPS2 Board has 4 GPIO controllers. These controllers are responsible for pin muxing, input/output, pull-up, etc.
All GPIO controller pins are exposed via the following sequence of pin numbers:
- Pins 0 - 15 are for GPIO 0 
- Pins 16 - 31 are for GPIO 1 
- Pins 32 - 47 are for GPIO 2 
- Pins 48 - 51 are for GPIO 3 
Mapping from the ARM MPS2 Board pins to GPIO controllers:
- D0 : EXT_0 
- D1 : EXT_4 
- D2 : EXT_2 
- D3 : EXT_3 
- D4 : EXT_1 
- D5 : EXT_6 
- D6 : EXT_7 
- D7 : EXT_8 
- D8 : EXT_9 
- D9 : EXT_10 
- D10 : EXT_12 
- D11 : EXT_13 
- D12 : EXT_14 
- D13 : EXT_11 
- D14 : EXT_15 
- D15 : EXT_5 
- D16 : EXT_16 
- D17 : EXT_17 
- D18 : EXT_18 
- D19 : EXT_19 
- D20 : EXT_20 
- D21 : EXT_21 
- D22 : EXT_22 
- D23 : EXT_23 
- D24 : EXT_24 
- D25 : EXT_25 
- D26 : EXT_26 
- D27 : EXT_30 
- D28 : EXT_28 
- D29 : EXT_29 
- D30 : EXT_27 
- D31 : EXT_32 
- D32 : EXT_33 
- D33 : EXT_34 
- D34 : EXT_35 
- D35 : EXT_36 
- D36 : EXT_38 
- D37 : EXT_39 
- D38 : EXT_40 
- D39 : EXT_44 
- D40 : EXT_41 
- D41 : EXT_31 
- D42 : EXT_37 
- D43 : EXT_42 
- D44 : EXT_43 
- D45 : EXT_45 
- D46 : EXT_46 
- D47 : EXT_47 
- D48 : EXT_48 
- D49 : EXT_49 
- D50 : EXT_50 
- D51 : EXT_51 
Peripheral Mapping:
- UART_3_RX : D0 
- UART_3_TX : D1 
- SPI_3_CS : D10 
- SPI_3_MOSI : D11 
- SPI_3_MISO : D12 
- SPI_3_SCLK : D13 
- I2C_3_SDA : D14 
- I2C_3_SCL : D15 
- UART_4_RX : D26 
- UART_4_TX : D30 
- SPI_4_CS : D36 
- SPI_4_MOSI : D37 
- SPI_4_MISO : D38 
- SPI_4_SCK : D39 
- I2C_4_SDA : D40 
- I2C_4_SCL : D41 
For more details please refer to MPS2 Technical Reference Manual (TRM).
System Clock
The V2M MPS2 main clock is 24 MHz.
Serial Port
The V2M MPS2 processor has five UARTs. Both the UARTs have only two wires for RX/TX and no flow control (CTS/RTS) or FIFO. The Zephyr console output, by default, is utilizing UART0.
Programming and Debugging
Flashing
V2M MPS2 provides:
- A USB connection to the host computer, which exposes a Mass Storage and an USB Serial Port. 
- A Serial Flash device, which implements the USB flash disk file storage. 
- A physical UART connection which is relayed over interface USB Serial port. 
Flashing an application to V2M MPS2
Here is an example for the Hello World application.
# From the root of the zephyr repository
west build -b mps2/an383 samples/hello_world
Connect the V2M MPS2 to your host computer using the USB port and you should see a USB connection which exposes a Mass Storage and a USB Serial Port. Copy the generated zephyr.bin in the exposed drive. Reset the board and you should be able to see on the corresponding Serial Port the following message:
Hello World! arm
Running an applicatoin with FVP
Here is the same example for running with FVP.
Set the ARMFVP_BIN_PATH environment variable to the location of your FVP you have downloaded from here
export ARMFVP_BIN_PATH=/home/../FVP_MPS2/
Then build with the same command you would use normally, and run with west build -t run_armfvp.