SC OBC TRCH Firmware

This is for SC-OBC A1001. Do NOT use it for EM1.

How to build and program

Prerequisite

$ xc8-cc --version
Microchip MPLAB XC8 C Compiler V2.46
Build date: Jan  4 2024
Part Support Version: 2.46
Copyright (C) 2024 Microchip Technology Inc.

$ cd trch-firmware
$ git describe
release-v1.0-28-g7ec231d

Build

You need GNU Make in addition to Microchip MPLAB XC8 Compiler to build it. We currently support v2.46.

   $ make | grep -v -e 'advisory: (2100)'
	CC src/main.p1
	CC src/fpga.p1
	CC src/interrupt.p1
	CC src/timer.p1
	CC src/ioboard.p1
	CC src/i2c-gpio.p1
	CC src/ina3221.p1
	CC src/spi.p1
	CC src/tmp175.p1
	CC src/usart.p1
	AR src/libdevice.a
	HEX hex/trch-firmware.hex
   src/fpga.c:62:: warning: (520) function "_fpga_is_i2c_accessible" is never called
   src/fpga.c:28:: warning: (759) expression generates no code
   src/fpga.c:43:: warning: (759) expression generates no code

   Memory Summary:
	Program space        used   59Ch (  1436) of  2000h words   ( 17.5%)
	Data space           used    65h (   101) of   170h bytes   ( 27.4%)
	EEPROM space         used     0h (     0) of   100h bytes   (  0.0%)
	Configuration bits   used     1h (     1) of     1h word    (100.0%)
	ID Location space    used     0h (     0) of     4h bytes   (  0.0%)

Program

You need a Microchip MPLAB IPE and MPLAB PICkit4. Make sure it works on your system and do the following.

$ make program

Pins and Signals

https://docs.google.com/spreadsheets/d/1tDlF5Ewv5WGajEHtzYHvV77b9ePaPVuW5S8i3cOUTzY/edit?usp=sharing

Domain

Whether a pin is strictly used by the system, or open to User, or reserved and not available to neither. “User (Shared)” is basically for Users but because the signals are shared between TRCH and the FPGA, the system disables them by setting INPUT when the FPGA is active.

Categroy

A name of a function which groups pins.

Control

Pins used for controling the FPGA behaviour are categorized as “Control”.

Diagnosis

Pins which Users can use to diagnose the system when something goes wrong. Users can only read the pins level.

User

Pins fully open for Users are in this category.

Pin Function

Either pin is used as a GPIO or used for a function.

External Pull

Whether a pin has a pull-up, a pull-down, or none. If a pull-up, it is either VDD_3V3_SYS or VDD_3V3.

States

We have INIT, POWER_DOWN, POWER_OFF, POWER_UP, READY, CONFIG, ACTIVE, and ERROR.

INIT

This is a special state. This shows the first pin settings TRCH initializes to right after Power-on Reset. This state is not defined in the state machine. Please note that these pins are not guaranteed to stay with the initial values. Peripheral initialize functions in C will change to whatever it suites to.

POWER_DOWN

The state to power down the FPGA. You will be in this state after FPGAPWR_EN is deasserted and until VDD_3V3 is at the GND level. In fpga.h, this corresponds to FPGA_STATE_POWER_DOWN.

POWER_OFF

The state to indicate that the FPGA is fully powered off and VDD_3V3 is at the GND level. This corresponds to FPGA_STATE_POWER_OFF.

POWER_UP

The state when the FPGA is powering up. That is, from FPGAPWR_EN is asserted to VDD_3V3 is fully up.

READY

This indicates the FPGA is up and ready to be configured. This corresponds to FPGA_STATE_READY in the state machine.

CONFIG

While in this state, the FPGA is configuring. This represents FPGA_STATE_CONFIG in the source code.

ACTIVE

The FPGA is configured and running. FPGA_STATE_ACTIVE.

ERROR

When TRCH find the watchdog live pulse does not come from the FPGA, you’ll be in this state.

Dirs and Levels

TRCH pins’ directions and levels.

In

The pin is INPUT.

Out

The pin is OUTPUT.

High

The pin is driving HIGH.

LOW

The pin is driving LOW.

X

Level can be either HIGH or LOW depending on the system or a User’s request.

-

Doesn’t matter. Usually indicates a Level when a pin is configured as INPUT.