jobitjoseph / n76e003-sdcc-bsp

Small Device C Compiler Nuvoton N76E003 BSP

N76E003-SDCC

OpenNuvoton N76E003-BSP adopted for Small Device C Compiler (SDCC) with some defines to make Visual Studio Code happy

BSP itself compressed into a couple of bsp/N76E003.h and bsp/N76E003.c files with multiple auxiliary APIs/drivers located in the bsp and lib folders.

Originally BSP was developed with SDCC version 3.8.0 but should work fine with any more recent versions as well.

Repository structure:

├── .vscode : some Visual Code settings and common tasks
│   └── tasks.json: defines the following tasks:
│       ├── build: build in the current folder
│       ├── clean: make clean in the current folder
│       ├── re-build: make clean; make; in the current folder
│       ├── erase device: erase all memory types and configuration bytes
│       └── flash device: flash the image from the current folder
├── bsp : common system files
│   ├── N76E003.c/h: main definitions for N76E003
│   ├── adc.c/h: ADC bandgap for calculating Vdd value
│   ├── event.c/h: simple ring buffer for generating events from ISRs
│   ├── i2c.c/h: I2C bus APIs
│   ├── iap.c/h: In Application Programming routines to read/write MCU flash memory
│   ├── irq.c/h: interrupts handling APIs
│   ├── key.c/h: simple driver for keys (push buttons) connected to pull-up pins
│   ├── key.svg: diagram of keys handling and events generation
│   ├── pinterrupt.c/h: pin interrupt handling APIs
│   ├── pwm.c/h: PWM handling APIs
│   ├── terminal.c/h: serial communication APIs enough to support simple CLI with one line history
│   ├── tick.c/h: wake-up timer (WKT) interrupt to provide milliseconds tick events
│   └── uart.c/h: UART 0/1 APIs.
├── lib : library of common drivers
│   ├── bv4618.c/h: BV4618 LCD controller driver
│   ├── dht.c/h: DHT/AM2302 relative humidity/temperature driver
│   ├── ds3231.c/h: DS3231 Real Time Clock driver
│   ├── dump.c/h: simple pretty printer for memory dumps
│   ├── ht1621.c/h: Holtek HT1621 RAM Mapping 32x4 LCD Controller driver
│   ├── i2c_mem.c/h: I2C EEPROM 24C* driver
│   ├── lcd_lpwm.c/h: driver for LCD used to XY-LPWM and clone boards
│   ├── pcf8574.c/h: I2C I/O Extender PCF8574 driver
│   ├── pwm_range.c/h: helper functions to specify PWM frequency ranges
│   └── srfs.c: read any SFR register by its address
├── pys : python scripts
│   └── size-mcs51.py: .mem file parser for mcs51 target generated by sdcc linker
├── xsamples
│   ├── bsp-pwm: testing PWM capabilities of N76E003
│   ├── bsp-spi: test different SPI configuration options
│   ├── bsp-template: template project for the BSP
│   ├── bsp-test: testing environment for bsp/lib
│   ├── hpdl-1414: HPDL-1414 Alphanumeric display example
│   ├── xy-lpwm-fw: alternative firmware for XY-LPWM and clones
│   └── xy-lpwm-lcd: XY-LPWM LCD screen controlled by commands over serial port
└── readme.md: this file

bsp-pwm provides examples of PWM configurations and PWM interrupt processing.

bsp-spi test some of SPI configuration options and use of SPSR::TXBUF flag.

bsp-template provides skeleton example for the BSP.

bsp-test provides examples of connecting different sensors/devices to N76E003 development board:

• DHT22 (AM2302) humidity/temperature sensor
• RTC DS3231 with I2C EEPROM Atmel 24C32 on board
• 20x4 LCD with BV4618 as I2C controller
• 16x4 LCD with PCF8574 as I2C controller
• PS/2 Mini Keyboard UK Layout
• HT16K33 based quad alphanumeric display

hpdl-1414 HPDL-1414 Alphanumeric display controlled using MCP23017 I2C 16-Bit I/O Expander xy-lpwm-fw and xy-lpwm-lcd examples use popular XY-LPWM single channel PWM generator as a development board for N76E003.

XY-LPWM3 with 3 PWM channels would be even better dev board as it provides 8 keys instead or 4 and 3 PWM outputs instead of 1, example with XY-LPWM3 TDB.

Prerequisites

To compile any of the examples make sure that you have make (make from avr-gcc works just fine), sdcc and Nuvoton's ICP nulink in the path. If not, modify corresponding defines in the makefiles.

You also will need Python 3.x installed for size-mcs51.py to work.

This script parses .mem file generated by SDCC linker and list information about memory sections:

> size-mcs51.py main.mem
   Name              Start    End  Size   Max Spare
   ---------------- ------ ------ ----- ----- -----------
   REG BANKS        0x0000 0x000F     2     4     2
   IDATA            0x0000 0x008B   140   256   116
   OVERLAYS                           3
   STACK            0x008C 0x00FF   116   248   116
   EXTERNAL RAM     0x0001 0x00e6   230   768   538 70.1% free
   ROM/EPROM/FLASH  0x0000 0x36b7 14008 18432  4424 24.0% free

Visual Studio Code IntelliSence configuration expects SDCCPATH environment variable to point to SDCC installation folder (needed to access SDCC header files).

Reference

Nuvoton N76E003 official site https://www.nuvoton.com/products/microcontrollers/8bit-8051-mcus/low-pin-count-8051-series/n76e003/

NuMicro software development tools https://github.com/OpenNuvoton/Nuvoton_Tools

OpenNuvoton N76E003 BSP https://github.com/OpenNuvoton/N76E003-BSP

Small Device C Compiler http://sdcc.sourceforge.net/