AN500)

Overview

The mps2/an385, mps2/an386, and mps2/an500 board targets are three of the mps2 Armv7-m based board targets supported in Zephyr. This document provides details about the support provided for these three Armv7-m mps2 board targets (AN385, AN386, AN500) 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, these board targets can also use FVP to emulate the platforms running on the MPS2+.

More information about the board can be found at the V2M MPS2 Website.

The application note for each of the board can be found as follows:

AN385 can be found at Application Note AN385
AN386 can be found at Application Note AN386
AN500 can be found at Application Note AN500

AN385 is also supported to run with QEMU, and is set to run with QEMU by default.

Note

These board targets makes no claims about its suitability for use with actual MPS2 hardware systems, or any other hardware system.

Hardware

ARM V2M MPS2 provides the following hardware components:

ARM Cortex-M Chip
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/an385, mps2/an386, and mps2/an500 board targets support 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_an385_defconfig or similarly in mps2_anxxx_defconfig for the other applicable boards.

Interrupt Controller

MPS2 is a Cortex-M based SoC and has 15 fixed exceptions and 45 IRQs.

A Cortex-M3/4/7-based board uses vectored exceptions. This means each exception calls a handler directly from the vector table.

Handlers are provided for exceptions 1-6, 11-12, and 14-15. The table here identifies the handlers used for each exception.

Exc#	Name	Remarks	Used by Zephyr Kernel
1	Reset		system initialization
2	NMI		system fatal error
3	Hard fault		system fatal error
4	MemManage	MPU fault	system fatal error
5	Bus		system fatal error
6	Usage fault	undefined instruction, or switch attempt to ARM mode	system fatal error
11	SVC		system calls, kernel run-time exceptions, and IRQ offloading
12	Debug monitor		system fatal error
14	PendSV		context switch
15	SYSTICK		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 with AN385.

# From the root of the zephyr repository
west build -b mps2/an385 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.