URL:
<http://savannah.nongnu.org/bugs/?37772>
Summary: wdt_enable() doesn't work for a list of chips
Project: AVR C Runtime Library
Submitted by: None
Submitted on: Пнд 19 Ноя 2012 07:29:10
Category: Header
Severity: 3 - Normal
Priority: 5 - Normal
Item Group: Header files
Status: None
Percent Complete: 0%
Assigned to: None
Originator Email: zombi...@gmail.com
Open/Closed: Open
Discussion Lock: Any
Release: Any
Fixed Release: None
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Details:
wdt can't be enabled because of wrong assembler instruction order in wdt.h
#define wdt_enable(value) \
__asm__ __volatile__ ( \
"in __tmp_reg__,__SREG__" "\n\t" \
"cli" "\n\t" \
"wdr" "\n\t" \
"sts %0,%1" "\n\t" \
"out __SREG__,__tmp_reg__" "\n\t" \
"sts %0,%2" "\n\t" \
: /* no outputs */ \
: "M" (_SFR_MEM_ADDR(_WD_CONTROL_REG)), \
"r" (_BV(_WD_CHANGE_BIT) | _BV(WDE)), \
"r" ((uint8_t) ((value & 0x08 ? _WD_PS3_MASK : 0x00) | \
_BV(WDE) | (value & 0x07)) ) \
: "r0" \
)
"sts" instructions must follow one another, as they must be completed within 4
clock cycles (according to datasheets)
So, correct version is this:
#define wdt_enable(value) \
__asm__ __volatile__ ( \
"in __tmp_reg__,__SREG__" "\n\t" \
"cli" "\n\t" \
"wdr" "\n\t" \
"sts %0,%1" "\n\t" \
"sts %0,%2" "\n\t" \
"out __SREG__,__tmp_reg__" "\n\t" \
: /* no outputs */ \
: "M" (_SFR_MEM_ADDR(_WD_CONTROL_REG)), \
"r" (_BV(_WD_CHANGE_BIT) | _BV(WDE)), \
"r" ((uint8_t) ((value & 0x08 ? _WD_PS3_MASK : 0x00) | \
_BV(WDE) | (value & 0x07)) ) \
: "r0" \
)
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