1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
|
/*
serial.c for using FreeRTOS
Copyright (C) 2005 Robotronics Inc.
*/
/* BASIC INTERRUPT DRIVEN SERIAL PORT DRIVER for port 1.
GCC demo modifications by Jeff Smith, Robotronics Inc. 2005
*/
#include "cpu.h"
#include <sys/sio.h>
/* Scheduler include files. */
#include "FreeRTOS.h"
#include "queue.h"
#include "task.h"
/* Demo application include files. */
#include "sci.h"
#include "serial.h"
/* The queues used to communicate between the task code and the interrupt
service routines. */
static QueueHandle_t xRxedChars;
static QueueHandle_t xCharsForTx;
/* Interrupt identification bits. */
#define serOVERRUN_INTERRUPT ( '\x08' )
#define serRX_INTERRUPT ( 0x20 )
#define serTX_INTERRUPT ( 0x80 )
/*-----------------------------------------------------------*/
/*
* Initialise port for interrupt driven communications.
*/
xComPortHandle xSerialPortInitMinimal( unsigned long ulWantedBaud, unsigned portBASE_TYPE uxQueueLength )
{
/* Hardware setup is performed by the Processor Expert generated code.
This function just creates the queues used to communicate between the
interrupt code and the task code - then sets the required baud rate. */
xRxedChars = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( signed char ) );
xCharsForTx = xQueueCreate( uxQueueLength, ( unsigned portBASE_TYPE ) sizeof( signed char ) );
SCI_SetBaudRateMode( ( char ) ulWantedBaud );
return NULL;
}
/*-----------------------------------------------------------*/
signed portBASE_TYPE xSerialGetChar( xComPortHandle pxPort, signed char *pcRxedChar, TickType_t xBlockTime )
{
/* Get the next character from the buffer queue. Return false if no characters
are available, or arrive before xBlockTime expires. */
if( xQueueReceive( xRxedChars, pcRxedChar, xBlockTime ) )
{
return pdTRUE;
}
else
{
return pdFALSE;
}
}
/*-----------------------------------------------------------*/
signed portBASE_TYPE xSerialPutChar( xComPortHandle pxPort, signed char cOutChar, TickType_t xBlockTime )
{
/* Place the character in the queue of characters to be transmitted. */
if( xQueueSend( xCharsForTx, &cOutChar, xBlockTime ) != pdPASS )
{
return pdFAIL;
}
/* Turn on the Tx interrupt so the ISR will remove the character from the
queue and send it. This does not need to be in a critical section as
if the interrupt has already removed the character the next interrupt
will simply turn off the Tx interrupt again. */
SCICR2 |= 0x80; // TIE
return pdPASS;
}
/*-----------------------------------------------------------*/
void vSerialClose( xComPortHandle xPort )
{
/* Not supported. */
//( void ) xPort;
}
/*-----------------------------------------------------------*/
/*
* Interrupt service routine for the serial port. Must be in non-banked
* memory.
*/
void ATTR_INT ATTR_NEAR vCOM_ISR( void );
void vCOM_ISR( void )
{
volatile unsigned char ucByte, ucStatus;
portBASE_TYPE xHigherPriorityTaskWoken = pdFALSE;
/* What caused the interrupt? */
ucStatus = SCISR1;
if( ucStatus & serOVERRUN_INTERRUPT )
{
/* The interrupt was caused by an overrun. Clear the error by reading
the data register. */
ucByte = SCIDRL;
}
else
if( ucStatus & serRX_INTERRUPT )
{
/* The interrupt was caused by a character being received.
Read the received byte. */
ucByte = SCIDRL;
/* Post the character onto the queue of received characters - noting
whether or not this wakes a task. */
xQueueSendFromISR( xRxedChars, ( void * ) &ucByte, &xHigherPriorityTaskWoken );
}
if( ( ucStatus & serTX_INTERRUPT ) && ( SCICR2 & 0x80 ) )
{
/* The interrupt was caused by a character being transmitted. */
if( xQueueReceiveFromISR( xCharsForTx, ( void * ) &ucByte, &xHigherPriorityTaskWoken ) == pdTRUE )
{
/* Clear the SCRF bit. */
SCIDRL = ucByte;
}
else
{
/* Disable transmit interrupt */
SCICR2 &= ~0x80; // TIE
}
}
if( xHigherPriorityTaskWoken )
{
portYIELD();
}
}
|
