PIC32MZ Starter Kit

Tags: arch:mips chip:pic32mz

Documentation for the NuttX port to the Microchip PIC32MZ Embedded Connectivity (EC) Starter Kit.

There are two configurations of the Microchip PIC32MZ Embedded Connectivity (EC) Starter Kit:

  1. The PIC32MZ Embedded Connectivity Starter Kit based on the PIC32MZ2048ECH144-I/PH chip (DM320006), and

  2. The PIC32MZ Embedded Connectivity Starter Kit based on the PIC32MZ2048ECM144-I/PH w/Crypto Engine (DM320006-C)

See www.microchip.com for further information.

Note

As of this writing (2015-03-01), the basic port is complete including minimal support for the NuttShell (NSH) over UART1. No testing has yet been performed due to seemingly insurmountable debug problems:

Thusfar, no one has been successful using NuttX with MPLABX. All debug is being performed using a J-Link debugger via some custom interconnect boards.

Patches were provided by Kristopher Tate on 2015-03-21 that support the serial console with the NuttShell, completing the basic bring-up.

Features

  • On-board crystal or oscillator for precision microcontroller clocking (24 MHz).

  • 32 kHz oscillator for RTCC and Timer1 (optional).

  • Three push button switches for user-defined inputs.

  • Three user-defined indicator LEDs.

  • USB Type A receptacle connectivity for PIC32 host-based applications.

  • USB Type micro-AB receptacle for OTG and USB device connectivity for PIC32 OTG/device-based applications.

  • Daughter board connectors for flexible Ethernet PHY options.

  • 50 MHz Ethernet PHY oscillator.

  • External 4 GB SQI memory for expanded memory applications.

  • PIC24FJ256GB106 USB microcontroller for on-board debugging.

  • USB connectivity for on-board debugger communications.

  • Regulated +3.3V power supply for powering the starter kit through USB or expansion board.

  • Connector for various expansion boards.

The PIC32MZ starter kit comes complete with a LAN8740 PHY daughter board.

Testing was performed with the following additional hardware:

  • Microchip PIC32MZ Embedded Connectivity (EC) Adapter Board (AC320006) that allows connection of the PIC32MZEC Starter Kit to the Microchip Multimedia Expansion Board (MEB, DM320005) or PIC32 I/O Expansion Board (DM320002). These were previously used with the PIC32MX bringup.

  • Microchip Multimedia Expansion Board II (MEB II, DM320005-2).

Buttons and LEDs

The PIC32MZ Ethernet Starter kit has 3 user LEDs labelled LED1-3 on the board:

PIN

LED

Notes

RH0

LED1

High illuminates (RED)

RH1

LED3

High illuminates (YELLOW)

RH2

LED2

High illuminates (GREEN)

If CONFIG_ARCH_LEDS is defined, then NuttX will control these LEDs as follows:

Status

LED1

LED2

LED3

LED1

LED2

LED3

LED_STARTED 0

OFF

OFF

OFF

—

—

—

LED_HEAPALLOCATE 1

ON

OFF

N/C

—

—

—

LED_IRQSENABLED 2

OFF

ON

N/C

—

—

—

LED_STACKCREATED 3

ON

ON

N/C

—

—

—

LED_INIRQ 4

N/C

N/C

ON

N/C

N/C

OFF

LED_SIGNAL 4

N/C

N/C

ON

N/C

N/C

OFF

LED_ASSERTION 4

N/C

N/C

ON

N/C

N/C

OFF

LED_PANIC 5

ON

N/C

N/C

OFF

N/C

N/C

The PIC32MZ Ethernet Starter kit has 3 user push buttons labelled SW1-3 on the board:

PIN

LED

Notes

RB12

SW1

Active-low

RB13

SW2

Active-low

RB14

SW3

Active-low

The switches do not have any debounce circuitry and require internal pull-up resistors. When idle, the switches are pulled high (+3.3V), and they are grounded when pressed.

Serial Console

MEB-II

By default, the UART1 is configured for the pins used by the MEB-II board. The UART1 signals are available at the MEB-II PICTail connector:

PIC32MZ PIN

CONNECTOR

MEB-II PIN

PICTAIL PIN

FUNCTION

J1

NAME

J2

RPA14/SCL1/RA14

124

SCL1/TOUCH_SCL

4

RPA15/SDA1/RA15

126

SDA1/TOUCH_SDA +3.3V GND

6 1,26 28

This pin selection is controlled by these definitions in pic32mz-starterkit/include/board.h:

#define BOARD_U1RX_PPS  U1RXR_RPA14
#define BOARD_U1TX_PPS  U1TX_RPA15R

PIC32MX I/O Expansion Board with Adapter Board

If the MEB-II UART configuration when used with the I/O Expansion board (with the adapter), then UART will be on J11 with Pin 35 being U1RX (into MZ) and Pin 37 being TU1X (out of MZ).

Directly from the Adapter Board

But you can get serial port directly from the PIC32MZ Embedded Connectivity (EC) Adapter Board (AC320006). The Microchip adapter board brings out UART signals as follows:

JP7 redirects J1 U3_TX to either J2 SOSCO/RC14 or U1_TX:

Adapter

JP7:

  • Pin 1: J2 Pin 32, SOSCO/RC14

  • Pin 2: J1 Pin 17, U3_TX

  • Pin 3: J2 Pin 90, U1_TX

PIC32MZ Starter Kit

J1 Pin 17, SOSCO/RC14 PIC32MZ SOSCO/RPC14/T1CK/RC14

RPC14 supports U1RX, U4RX, and U3TX

JP8 redirects J1 RB3/AN3/SDO4/WIFI_SDI to either J2 AN3/SDO4/WIFI_SDI or U3_RX:

Adapter

JP8:

  • Pin 1: J2, Pin 66

  • Pin 2: J1, Pin 105

  • Pin 3: J2, Pin 88

PIC32MZ Starter Kit

  • AN3/SDO4/WIFI_SDI

  • RB3/AN3/SDO4/WIFI_SDI

  • U3_RX

PIC32MZ Starter Kit

J1, Pin 105, AN3/C2INA/RPB3/RB3

RPB3 supports U3RX, U1TX, and U5TX

Thus UART1 or UART3 could be used as a serial console if only the PIC32MZEC Adapter Board is connected.

The default serial configuration here in these configurations is UART1 using RPC14 and RPB3. That UART selection can be change by running ‘make menuconfig’. The UART pin selections would need to be changed by editing boards/pc32mz-starterkit/include/board.h.

If using a AC320006 by itself, JP7 pin 2 and JP8 pin 2 is where you would connect a 3.3 Volt TTL serial interface.

For a configuration using UART1 connect:

  • TX to AC320006-JP7 pin 2 which is PIC32MZ pin 106 (RPC14) used as U1RX

  • RX to AC320006-JP8 pin 2 which is PIC32MZ pin 31 (RPB3)) used as U1TX

For a configuration using For UART3 connect:

  • TX to AC320006-JP8 pin 2 which is PIC32MZ pin 31 (RPB3)) used as U3RX

  • RX to AC320006-JP7 pin 2 which is PIC32MZ pin 106 (RPC14) used as U3TX

If using a AC320006 plugged into a DM320002 then regardless of which UART, UART1 or UART3 is configured in software, the jumpers on the AC320006 are the same, just the signal directions and UART changes.

  • AC320006-JP7 connect pin 2 to pin 3. U1RX U3TX

  • AC320006-JP8 connect pin 2 to pin 3. U1TX U3RX

For the default configuration using UART1 the PIC32MZ pin 106 (RPC14) will be configured as U1RX and is tied to the AC320006’s JP7 Pin 2. With the jumpers as listed above, once the AC320006 is plugged into the DM320002, the PIC32MZ U1RX will be connected to the DM320002’s J11 pin 43. The DM320002’s J11 pin 43 should then be connected to the TX of a 3.3 volt TTL serial converter such as a FTDI TTL232RG. For the FTDI TTL232RG TX is the orange wire.

Likewise the PIC32MZ pin 31 (RPB3) will be configured as U1TX and is tied to the AC320006’s JP8 Pin 2. With the jumpers as listed above, once the AC320006 is plugged into the DM320002, the PIC32MZ’ U1TX will be connected to the DM320002’s J11 pin 41. The DM320002’s J11 pin 41 should then be connected to the RX signal of a 3.3 volt TTL serial converter. For the FTDI TTL232RG RX is the yellow wire.

For the alternate configuration using UART3 the PIC32MZ pin 106 (RPC14) will be configured as U3TX and is tied to the AC320006’s JP7 Pin 2. With the jumpers as listed above, once the AC320006 is plugged into the DM320002, the PIC32MZ U3TX will be connected to the DM320002’s J11 pin 43. The DM320002’s J11 pin 43 should then be connected to the RX of a 3.3 volt TTL serial converter such as a FTDI TTL232RG. For the FTDI TTL232RG TX is the yellow wire.

Likewise the PIC32MZ pin 31 (RPB3) will be configured as U3RX and is tied to the AC320006’s JP8 Pin 2. With the jumpers as listed above, once the AC320006 is plugged into the DM320002, the PIC32MZ’ U3RX will be connected to the DM320002’s J11 pin 41. The DM320002’s J11 pin 41 should then be connected to the TX signal of a 3.3 volt TTL serial converter. For the FTDI TTL232RG RX is the orange wire.

board.h Header File Changes

The board configuration is currently set up to use the serial console on the MEB-II board. If you want to use the adapter board directly, you will need to change pic32mz-starterkit/include/board.h as follows:

-#define BOARD_U1RX_PPS  U1RXR_RPA14
-#define BOARD_U1TX_PPS  U1TX_RPA15R
+#define BOARD_U1RX_PPS  U1RXR_RPC14
+#define BOARD_U1TX_PPS  U1TX_RPB3R

On Board Debug Support

The starter kit includes a PIC24FJ256GB106 USB microcontroller that provides debugger connectivity over USB. The PIC24FJ256GB106 is hard-wired to the PIC32 device to provide protocol translation through the I/O pins of the PIC24FJ256GB106 to the ICSP™ pins of the PIC32 device.

If MPLAB® REAL ICE™ or MPLAB ICD 3 is used with the starter kit, disconnect the onboard debugger from the PIC32 device by removing the jumper JP2. When the on-board debugger is required, replace the jumper JP2. When the jumper JP2 is installed, pin 1 must be connected to pin 3 and pin 2 must be connected to pin 4.

Flashing

Creating Compatible NuttX HEX files

Intel Hex Format Files

When NuttX is built it will produce two files in the top-level NuttX directory:

  1. nuttx: This is an ELF file

  2. nuttx.hex: This is an Intel Hex format file. This is controlled by the setting CONFIG_INTELHEX_BINARY in the .config file.

The PICkit tool wants an Intel Hex format file to burn into FLASH. However, there is a problem with the generated nuttx.hex: The tool expects the nuttx.hex file to contain physical addresses. But the nuttx.hex file generated from the top-level make will have address in the KSEG0 and KSEG1 regions.

tools/pic32/mkpichex

There is a simple tool in the NuttX tools/pic32 directory that can be used to solve both issues with the nuttx.hex file. But, first, you must build the tool:

$ cd tools/pic32
$ make -f Makefile.host

Now you will have an executable file called mkpichex (or mkpichex.exe on Cygwin). This program will take the nuttx.hex file as an input, it will convert all of the KSEG0 and KSEG1 addresses to physical address, and it will write the modified file, replacing the original nuttx.hex.

To use this file, you need to do the following things:

$ export PATH=???  # Add the NuttX tools/pic32 directory to your
                   # PATH variable
$ make             # Build nuttx and nuttx.hex
$ mkpichex $PWD    #  Convert addresses in nuttx.hex.  $PWD is the path
                   # to the top-level build directory.  It is the only
                   # required input to mkpichex.

This procedure is automatically performed at the end of a build.

Tool Issues

Pinquino Toolchain

If you use the Pinguino toolchain, you will probably see this error:

$ C:\pinguino-11\compilers\p32\bin\p32-ld.exe: target elf32-tradlittlemips not found

This is due to linker differences in the toolchains. The linker script at boards/pic32mz-starterkit has:

OUTPUT_FORMAT("elf32-tradlittlemips")

This error can be eliminated with the Pinguino toolchain by changing this to:

OUTPUT_FORMAT("elf32-littlemips")

Mentor Toolchain

https://sourcery.mentor.com/GNUToolchain/release2934 tools.

If you use this toolchain, you will need to add CROSSDEV=mips-sde-elf- to your Make.defs file.

ICD3

The onboard debugger is Slow and one is better off using an ICD3. By removing jumper JP2, I can disable the on-board OpenHCD debugger an enable the RJ11 debug connector. My ICD 3 does seems to work properly using this configuration, at least in the sense that it is recognized by both MPLABX IDE and IPE.

Configurations

You can use the following command to configure the NuttX build, where <config> is one of the configurations listed below:

$ tools/configure.sh pic32mz-starterkit:<config>

By default, the Pinguino MIPs tool chain is used. This toolchain selection can easily be changed with make menuconfig.

nsh

This is the NuttShell (NSH) using the NSH startup logic at apps/examples/nsh.

This configuration has UART1 enabled as a serial console. This can easily be changed by reconfiguring with make menuconfig.

These are other things that you may want to change in the configuration:

  • CONFIG_ARCH_CHIP_PIC32MZ2048ECM=y: Assumes part with Crypto Engine

  • CONFIG_PIC32MZ_DEBUGGER_ENABLE=n: Debugger is disabled

  • CONFIG_PIC32MZ_TRACE_ENABLE=n: Trace is disabled

  • CONFIG_PIC32MZ_JTAG_ENABLE=n: JTAG is disabled