Embedded Ethernet Module (A3053) Manual

Contents

Description

[06-AUG-25] The Embedded Ethernet Module (EEM, A3053) is an Ethernet module on an Mini PCI Express (mPCIE) board. It provides and Ethernet interface, a TCP/IP stack, and thirty-five programmable input-outputs. The Ethernet interface is wired 10Base-T and 100Base-T. There is no RJ-45 socket mounted on the mPCIE card. The Ethernet connections run off the board to an external RJ-45 connector. The heart of the A3053 is a PIC32MZ2048EFH100 Embedded Connectivity with Floating Point Unit microcontroller. This thirty-two bit microcontroller uses Microchip's MIPS32 M4K instruction set, runs at 200 MHz and is equipped with 2 MByte of program memory and 512 KByte of data memory. It provides fifty-one reprogrammable input-output pins, including forty 12-Bit analog-to-digital converter (ADC) inputs, and pulse width modulators to mimic digital to analog converters (DACs). To compile and program the microcontroller, we use Microchip's MPLAB integrated development environment with its Harmony V3 TCP/IP stack. The microcontroller provides its own media access controller (MAC), but the Ethernet physical layer is external to the microcontroller, in the form of a LAN8720A, which we mount on the A3053 board.

Figure: The Discontinued RCM6700 Mini-Core Module. When programmed correctly, the A3053A will act as a drop-in replacement for the RCM6700 in all our network-enabled instruments.

The A3053 is currently in development with an expected release data of January 2026. The A3053A is intended to be a drop-in replacement for the hardware provided by the discontinued RCM6700 from the former manufacturer Rabbit Semiconductor. We used the RCM6700 for fifteen years in our LWDAQ Relays, which includes our LWDAQ Driver (A2071E), Animal Location Tracker (ALT), Telemetry Control Box (TCB), and Power Over Ethernet Function Generator (A3052). We will be equipping all these instruments with A3053 modules as soon as they are available. Our stock of RCM6700s is dwindling.

RCM6700 Compatibility

[06-AUG-25] The A3053A is intended as a drop-in replacement for the RCM6700. Let us begin by stating the incompatibilities between the A3053A and the RCM6700. The A3053 does not provide a standby power mode in which it can be kept active with only a few microamperes of quiescent current. The RCM6700 external battery connection is used on the A3053 a JTAG programming input. If we begin with a board designed for the RCM6700, upon which there exists an RCM6700 programming plug, we can use this plug as an ICSP programming port for the A3053A, but we need an adaptor. The RCM6700 programming plug is a 2×5 0.05" rectangular plug such as the GRPB052VWQS-RC while the ICSP programming cables expect a 0.1" 1×6 rectangular plug such as the PRPC006SACN-RC. Starting with a LPPB052CFFN-RC 2×5 receptacle, we run wires to a 1×6 plug according to the table below. We plug our ICSP six-pin programming cable into our adaptor and plug our adaptor into the RCM6700 programming plug. We can now program the A3053A with the ICSP protocol.

In place of a 2.5-V Ethernet common-mode voltage, the A3053A produces 3.3 V. The A3053A's Ethernet physical layer operates perfectly well with 3.3 V, and is loaded on the A3053A board. The only time this change in voltage will be a problem is if the motherboard makes use of the 2.5-V RCM6700 output on mPCIe pin 8 to power other circuits that require 2.5 V. The A3053A does not have a reset signal generator. It requires that the mother board provide a reset signal input on mPCIe pin 16, which is the RCM6700 reset input pin, but it does not provide its own RESET output. Instead, it connects !RESET_IN on mPCIe pin 16 directly to !RESET on mPCIe pin 28. The motherboard must provide its own reset monitor, such as an MCP130, to detect power-up and also to debounce a motherboard reset switch.

The table below gives the connections between the PIC32MZ and the mPCIe connector, and includes the RCM6700 signal names for these same mPCIe pins. All RCM6700 control and input-output signals are routed to their own PIC32MZ general-purpose input-output (GPIO) pin. We have confirmed that in our own use of the RCM6700 the PIC32MZ pins we have assigned will serve the same purpose as in our original RCM6700 design, but we cannot claim that the PIC32MZ GPIOs we have assigned will, in all cases, allow for exact duplication of RCM6700 functions.

Design

[04-AUG-25] For design files and a chronological account of the development of the A3053, see its Design and Development page.