System Installation
NANO-8045 User’s Manual
3-6
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<< How to access W83627DHG WDT Configuration Register >>
Must enter extended function mode first , then follow the following steps for
accessing WDT registers.
Step(1) : CR2B_bit4P0
Initialize the multiplex pin ( pin89 ) to WDTO function
outportb ( EFIR , 0x2B ) ; // al_char1 : unsigned char
al_char1 = inportb ( EFDR ) & 0xEF ; // CR2B_bit4P0
outportb ( EFIR , 0x2B ) ; // init pin 89 to WDT
outportb ( EFDR , al_char1 ) ;
Step(2) : CR07_P08
Ponit to LD8.
outportb ( EFIR , 0x07 ) ;
outportb ( EFDR , 0x08 ) ;
Step(3) : LD8_CR30_bit0P1
Activate LD8
outportb ( EFIR , 0x30 ) ;
al_char1 = inportb ( EFDR ) | 0x01 ; // CR30_bit0P1
outportb ( EFIR , 0x30 ) ; // Activate LD8
outportb ( EFDR , al_char1 ) ;
Step(4) : LD8_CRF7_bit[7,6]P[0,0]
Not allow K/B and Mouse’s interrupts to reload WDT timer.
outportb ( EFIR , 0xF7 ) ;
al_char1 = inportb ( EFDR ) & 0x3F ; // CRF7_bit[7,6]P[0,0]
outportb ( EFIR , 0xF7 ) ;
outportb ( EFDR , al_char1 ) ;
Step(5) : Refresh WDT before it expires.
Once WDT expires , system will be reset.
LD8_CRF5_bit3 : 0 : second unit
1 : minute unit
LD8_CRF6 : T
wd
, “Writing 00” means “disable WDT”
1~255 time unit( time unit : second, minute )
Notes:
“CR2B_bit4P0“ means ”Write 0 to bit4 of Configuration Register 0x2B”.
