diff options
Diffstat (limited to 'iwrap/wd.h')
| -rw-r--r-- | iwrap/wd.h | 159 |
1 files changed, 159 insertions, 0 deletions
diff --git a/iwrap/wd.h b/iwrap/wd.h new file mode 100644 index 0000000000..99058f0331 --- /dev/null +++ b/iwrap/wd.h @@ -0,0 +1,159 @@ +/* This is from http://www.mtcnet.net/~henryvm/wdt/ */
+#ifndef _AVR_WD_H_
+#define _AVR_WD_H_
+
+#include <avr/io.h>
+
+/*
+Copyright (c) 2009, Curt Van Maanen
+
+Permission to use, copy, modify, and/or distribute this software for any
+purpose with or without fee is hereby granted, provided that the above
+copyright notice and this permission notice appear in all copies.
+
+THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+
+
+include usage-
+ #include "wd.h" //if in same directory as project
+ #include <avr/wd.h> //if wd.h is in avr directory
+
+set watchdog modes and prescale
+
+usage-
+ WD_SET(mode,[timeout]); //prescale always set
+
+modes-
+ WD_OFF disabled
+ WD_RST normal reset mode
+ WD_IRQ interrupt only mode (if supported)
+ WD_RST_IRQ interrupt+reset mode (if supported)
+
+timeout-
+ WDTO_15MS default if no timeout provided
+ WDTO_30MS
+ WDTO_60MS
+ WDTO_120MS
+ WDTO_250MS
+ WDTO_500MS
+ WDTO_1S
+ WDTO_2S
+ WDTO_4S (if supported)
+ WDTO_8S (if supported)
+
+examples-
+ WD_SET(WD_RST,WDTO_1S); //reset mode, 1s timeout
+ WD_SET(WD_OFF); //watchdog disabled (if not fused on)
+ WD_SET(WD_RST); //reset mode, 15ms (default timeout)
+ WD_SET(WD_IRQ,WDTO_120MS); //interrupt only mode, 120ms timeout
+ WD_SET(WD_RST_IRQ,WDTO_2S); //interrupt+reset mode, 2S timeout
+
+
+for enhanced watchdogs, if the watchdog is not being used WDRF should be
+cleared on every power up or reset, along with disabling the watchdog-
+ WD_DISABLE(); //clear WDRF, then turn off watchdog
+
+*/
+
+//reset registers to the same name (MCUCSR)
+#if !defined(MCUCSR)
+#define MCUCSR MCUSR
+#endif
+
+//watchdog registers to the same name (WDTCSR)
+#if !defined(WDTCSR)
+#define WDTCSR WDTCR
+#endif
+
+//if enhanced watchdog, define irq values, create disable macro
+#if defined(WDIF)
+#define WD_IRQ 0xC0
+#define WD_RST_IRQ 0xC8
+#define WD_DISABLE() do{ \
+ MCUCSR &= ~(1<<WDRF); \
+ WD_SET(WD_OFF); \
+ }while(0)
+#endif
+
+//all watchdogs
+#define WD_RST 8
+#define WD_OFF 0
+
+//prescale values
+#define WDTO_15MS 0
+#define WDTO_30MS 1
+#define WDTO_60MS 2
+#define WDTO_120MS 3
+#define WDTO_250MS 4
+#define WDTO_500MS 5
+#define WDTO_1S 6
+#define WDTO_2S 7
+
+//prescale values for avrs with WDP3
+#if defined(WDP3)
+#define WDTO_4S 0x20
+#define WDTO_8S 0x21
+#endif
+
+//watchdog reset
+#define WDR() __asm__ __volatile__("wdr")
+
+//avr reset using watchdog
+#define WD_AVR_RESET() do{ \
+ __asm__ __volatile__("cli"); \
+ WD_SET_UNSAFE(WD_RST); \
+ while(1); \
+ }while(0)
+
+/*set the watchdog-
+1. save SREG
+2. turn off irq's
+3. reset watchdog timer
+4. enable watchdog change
+5. write watchdog value
+6. restore SREG (restoring irq status)
+*/
+#define WD_SET(val,...) \
+ __asm__ __volatile__( \
+ "in __tmp_reg__,__SREG__" "\n\t" \
+ "cli" "\n\t" \
+ "wdr" "\n\t" \
+ "sts %[wdreg],%[wden]" "\n\t" \
+ "sts %[wdreg],%[wdval]" "\n\t" \
+ "out __SREG__,__tmp_reg__" "\n\t" \
+ : \
+ : [wdreg] "M" (&WDTCSR), \
+ [wden] "r" ((uint8_t)(0x18)), \
+ [wdval] "r" ((uint8_t)(val|(__VA_ARGS__+0))) \
+ : "r0" \
+)
+
+/*set the watchdog when I bit in SREG known to be clear-
+1. reset watchdog timer
+2. enable watchdog change
+5. write watchdog value
+*/
+#define WD_SET_UNSAFE(val,...) \
+ __asm__ __volatile__( \
+ "wdr" "\n\t" \
+ "sts %[wdreg],%[wden]" "\n\t" \
+ "sts %[wdreg],%[wdval]" "\n\t" \
+ : \
+ : [wdreg] "M" (&WDTCSR), \
+ [wden] "r" ((uint8_t)(0x18)), \
+ [wdval] "r" ((uint8_t)(val|(__VA_ARGS__+0))) \
+)
+
+
+//for compatibility with avr/wdt.h
+#define wdt_enable(val) WD_SET(WD_RST,val)
+#define wdt_disable() WD_SET(WD_OFF)
+
+
+#endif /* _AVR_WD_H_ */
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