AN4178

LIN demonstration software

Doc ID 23745 Rev 1

9/13

stm8s_it

This module contains the following interrupt routines:

●

External interrupt of the port E routine, and update of the UserButton1/UserButton2

software flag, when a falling edge is detected on the PE2/PE1 ports

●

CAN receive interrupt routine, which is not activated in the demonstration software (test

mode only)

●

LINUART receive/error interrupt routine, which implements the algorithm described in

Section 2.2.2: LINUART interrupt

●

TIM4 interrupt routine, which sets timebase ticks for LIN, CAN (not used in the

demonstration software), application, and L99PM62GXP watchdog refresh

4.2.3

STM8S/A standard peripheral library modules

The demonstration software is based on the STM8S/A standard peripheral library version

2.1.0, dated Nov 2011.

The following driver modules are used:

●

stm8s_exti.c, for the external interrupts on port E (USER1 and USER2 buttons)

●

stm8s_clk.c, for configuring clocks and enabling HSE

●

stm8s_gpio.c, for initializing, reading and updating all ports

●

stm8s_spi.c, for SPI communication with the L99PM62GXP device

●

stm8s_tim4.c, for generating a 1 ms timebase

●

stm8s_uart3.c, for initializing LINUART

Note:

LINUART is described as UART3 in the RM0016 STM8S and STM8A reference manual.

4.3

STM8AF LIN slave software description

4.3.1

STM8AF peripherals

The following STM8AF peripherals are used by the application:

●

SPI, which is used in master mode at 250 kHz to initialize the L99PM62GPX and

refresh its watchdog

●

TIM4, which allows generation of a 1 ms timebase

●

LINUART, which is used to perform LIN communication in slave mode. The automatic

resynchronization feature is enabled.

●

GPIO

–

PA3, PD3, PD0, PE3 and PC3 ports are used for LED display.

–

PE2 and PE1 are used for the USER1 and USER2 push buttons.

–

PC7, PC6, PC5 and PE5 are used respectively for the SPI MISO, MOSI, SCK and

NSS.

–

PD5 and PD6 are used for LINART TX and RX.