Priority arrangement
HH: RS485 Rx handler
H: Voltage control
M: Peripheral
L: SMR
void
COMM_Init()
{
Create mutex for RS485 driver.
Create a task, named RS485 Rx Handler.
}Create a task, named RS485 Rx Handler.
bool
RS485_TxHandler(byte *pPacket, bool waitSlave, portTypeTick delay )
{
if ( mutex is not available )
{
{
delay;
if ( mutex is still not available ) return false;
if ( mutex is still not available ) return false;
}
if ( waitSlave ) resume task, RS485 Rx Handler.
......
.....
other codes.
....
release the mutex.
}......
.....
other codes.
....
release the mutex.
void
Task_RS485_RxHandler()
{
byte c;
Suspend itselt;
for(;;)
{
Suspend itselt;
for(;;)
{
Delay 5ms.
while( RS485_GetByte( &c, delay_2ms ) )
{
while( RS485_GetByte( &c, delay_2ms ) )
{
if ( Get a legal RS485 Packet ) {
Signal semaphore, SEM_RS485_Arrive_Packet;
break;
break;
}
}
Suspend itself.
Suspend itself.
}
}Binary Semaphore : 用於Task之間的同步
Mutex : (MUTual EXclusion semaphores), are used by tasks to gain exclusive access to resources. A mutex is used by App to reduce the priority inversion problem.
