
Table B.1: Watchdog Timer Registers
| Address of | Attribute | Description | 
| register (2E) | 
 | 
 | 
| 
 | 
 | 
 | 
| Read/Write | Value (2F) | 
 | 
| 
 | and | 
 | 
| 
 | description | 
 | 
| 
 | 
 | 
 | 
| 87 (hex) | Write this address to I/O address | |
| 
 | 
 | port 2E (hex) twice to unlock the | 
| 
 | 
 | W83627HF | 
| 
 | 
 | 
 | 
| 07 (hex) | write | Write 08 (hex) to select register of | 
| 
 | 
 | watchdog timer. | 
| 
 | 
 | 
 | 
| 30 (hex) | write | Write 01 (hex) to enable the function | 
| 
 | 
 | of the watchdog timer. Disabled is | 
| 
 | 
 | set as default. | 
| 
 | 
 | 
 | 
| F5 (hex) | write | Set seconds or minutes as units for | 
| 
 | 
 | the timer. | 
| 
 | 
 | 
 | 
Write 0 to bit 3: set second as counting unit. [default]
Write 1 to bit 3: set minute as counting unit
| F6 (hex) | write | 0: stop timer [default]01~FF (hex): | 
| 
 | 
 | The amount of the count, in seconds | 
| 
 | 
 | or minutes, depends on the value | 
| 
 | 
 | set in register F5 (hex). This number | 
| 
 | 
 | decides how long the watchdog | 
| 
 | 
 | timer waits for strobe before gener- | 
| 
 | 
 | ating an interrupt or reset signal. | 
| 
 | 
 | Writing a new value to this register | 
| 
 | 
 | can reset the timer to count with the | 
| 
 | 
 | new value. | 
| 
 | 
 | 
 | 
| F7 (hex) | rd/wr | Bit 6: Write 1 to enable keyboard to | 
| 
 | 
 | reset the timer, 0 to disable.[default] | 
| 
 | 
 | Bit 5: Write 1 to generate a timeout | 
| 
 | 
 | signal immediately and automati- | 
| 
 | 
 | cally return to 0. [default=0] Bit 4: | 
| 
 | 
 | Read status of watchdog timer, 1 | 
| 
 | 
 | means timer is "time out". | 
| 
 | 
 | 
 | 
| AA (hex) | Write this address to I/O port 2E | |
| 
 | 
 | (hex) to lock the watchdog timer.2 | 
| 
 | 
 | 
 | 
| 40 |