Add 100Hz timer

Use Timer 1 to generate a 100Hz timer interrupt

diff --git a/Makefile b/Makefile
index 2fb248982b18e58833896ef1f524dbe1f0bc82aa..b6da6b8f63e0e028be9a25a2e3b72ea05f3484c1 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -21,6 +21,7 @@ INC = \
 
 SRC = \
        ao_task.c \
+       ao_timer.c \
        ao_panic.c \
        ao_test.c \
        _bp.c

diff --git a/ao.h b/ao.h
index 4fd368c00a5d0ef7e53b5a7301f4eb23076d94c6..2d434134b8ea4f6f01c63a2a2179daac127e3d99 100644 (file)
--- a/ao.h
+++ b/ao.h
@@ -22,7 +22,9 @@
 #include <stdio.h>
 #include "cc1111.h"
 
-#define AO_STACK_START 0x11
+#define DATA_TO_XDATA(a)       ((void __xdata *) ((uint8_t) (a) | 0xff00))
+
+#define AO_STACK_START 0x21
 #define AO_STACK_END   0xfe
 #define AO_STACK_SIZE  (AO_STACK_END - AO_STACK_START + 1)
 
@@ -36,6 +38,10 @@ struct ao_task {
 
 #define AO_ERROR_NO_TASK       1
 
+#define ao_interrupt_disable() (EA = 0)
+#define ao_interrupt_enable()  (EA = 1)
+
+/* ao_task.c */
 int ao_sleep(__xdata void *wchan);
 int ao_wakeup(__xdata void *wchan);
 void ao_add_task(__xdata struct ao_task * task, void (*start)(void));
@@ -43,4 +49,13 @@ void ao_start_scheduler(void);
 void ao_yield(void) _naked;
 void ao_panic(uint8_t reason);
 
+/* ao_timer.c */
+
+volatile __data uint16_t ao_time;
+
+void ao_timer_isr(void) interrupt 9;
+void ao_timer_init(void);
+uint16_t ao_time_atomic(void);
+void ao_delay(uint16_t ticks);
+
 #endif /* _AO_H_ */

diff --git a/ao_task.c b/ao_task.c
index 0af5043cd67738ea33c1976ce8b569f761c3f1de..0e976d7c4247e5e341c40684c2d62a8e2c59018c 100644 (file)
--- a/ao_task.c
+++ b/ao_task.c
@@ -181,5 +181,6 @@ ao_start_scheduler(void)
 {
        ao_cur_task_id = AO_NO_TASK;
        ao_cur_task = NULL;
+       ao_timer_init();
        ao_yield();
 }

diff --git a/ao_test.c b/ao_test.c
index 85d523af87dba08115f42de6ac3caece76727dc9..35a019fa025ee2c79bba84fef495e26ee37e39ce 100644 (file)
--- a/ao_test.c
+++ b/ao_test.c
@@ -45,7 +45,7 @@ blink_1(void)
 {
        for (;;) {
                P1 ^= 2;
-               delay(20);
+               ao_delay(20);
        }
 }
 
@@ -53,7 +53,7 @@ void
 wakeup(void)
 {
        for (;;) {
-               delay(10);
+               ao_delay(10);
                ao_wakeup(&blink_chan);
        }
 }
@@ -62,6 +62,9 @@ void
 main(void)
 {
        CLKCON = 0;
+       while (!(SLEEP & SLEEP_XOSC_STB))
+               ;
+
        /* Set p1_1 and p1_0 to output */
        P1DIR = 0x03;
        

diff --git a/ao_timer.c b/ao_timer.c
new file mode 100644 (file)
index 0000000..7a81f32
--- /dev/null
+++ b/ao_timer.c
@@ -0,0 +1,80 @@
+/*
+ * Copyright © 2009 Keith Packard <keithp@keithp.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA.
+ */
+
+#include "ao.h"
+
+volatile __data uint16_t ao_time;
+
+void ao_timer_isr(void) interrupt 9
+{
+       ++ao_time;
+       ao_wakeup(DATA_TO_XDATA(&ao_time));
+}
+
+uint16_t ao_time_atomic(void)
+{
+       uint8_t ret1;
+       uint16_t ret2;
+       
+       for (;;) {
+               ret1 = ao_time >> 8;
+               ret2 = ao_time;
+               if (ret1 == ((__xdata uint8_t *)(&ret2))[1])
+                       break;
+       }
+       return ret2;
+}
+
+#define T1_CLOCK_DIVISOR       8       /* 24e6/8 = 3e6 */
+#define T1_SAMPLE_TIME         30000   /* 3e6/30000 = 100 */
+
+void
+ao_timer_init(void)
+{
+       /* NOTE:  This uses a timer only present on cc1111 architecture. */
+
+       /* disable timer 1 */
+       T1CTL = 0;
+
+       /* set the sample rate */
+       T1CC0H = T1_SAMPLE_TIME >> 8;
+       T1CC0L = T1_SAMPLE_TIME;
+
+       T1CCTL0 = T1CCTL_MODE_COMPARE;
+       T1CCTL1 = 0;
+       T1CCTL2 = 0;
+
+       /* clear timer value */
+       T1CNTL = 0;
+
+       /* enable overflow interrupt */
+       OVFIM = 1;
+       /* enable timer 1 interrupt */
+       T1IE = 1;
+
+       /* enable timer 1 in module mode, dividing by 8 */
+       T1CTL = T1CTL_MODE_MODULO | T1CTL_DIV_8;
+}
+
+void
+ao_delay(uint16_t ticks)
+{
+       uint16_t until = ao_time_atomic() + ticks;
+
+       while ((int16_t) (until - ao_time_atomic()) > 0)
+               ao_sleep(DATA_TO_XDATA(&ao_time));
+}