RELIANCE 45C37B自動遠程I/O接口
圖4-7顯示了VMIVME-7740中如何使用看門狗定時器的通用框圖?？撮T狗定時器寄存器映射在NVRAM地址$D8000到$D800D的底部14個位置。表4-12顯示了每個看門狗寄存器的地址、內(nèi)容和范圍。寄存器0到A是時鐘、日歷和時間寄存器。寄存器B是命令寄存器。寄存器C和D是看門狗報警寄存器?？撮T狗定時器包含14個8位寬的寄存器。這些寄存器包含所有的時間、報警、看門狗、控制和數(shù)據(jù)信息。時鐘日歷、報警和看門狗寄存器具有包含數(shù)據(jù)副本的外部（用戶可訪問）和內(nèi)部存儲器位置。外部存儲器位置獨立于內(nèi)部功能，除了通過傳輸遞增的內(nèi)部值定期更新外。寄存器0、1、2、4、6、8、9和A包含時間和二進制編碼十進制（BCD）的數(shù)據(jù)信息。寄存器3、5和7包含BCD格式的每日時間報警信息。命令寄存器（寄存器B）包含二進制數(shù)據(jù)。
Figure 4-7 shows a generalized block diagram of how the Watchdog Timer is used in the VMIVME-7740. The Watchdog Timer registers are memory-mapped in the bottom fourteen locations of NVRAM addresses $D8000 through $D800D. Table 4-12 shows the address, content, and the range of each Watchdog Register.Registers 0 through A are Clock, Calendar, Time of Day Registers. Register B is the Command Register. Registers C and D are Watchdog Alarm Registers. The Watchdog Timer contains 14 registers which are 8-bits wide. These registers contain all of the Time of Day, Alarm, Watchdog, Control, and Data information. The Clock Calendar, Alarm, and Watchdog Registers have both external (user accessible) and internal memory locations containing copies of the data. The external memory locations are independent of the internal functions except that they are updated periodically by the transfer of the incremented internal values. Registers 0, 1, 2, 4, 6, 8, 9, and A contain Time of Day and Data information in Binary Coded Decimal (BCD). Registers 3, 5, and 7 contain the Time of Day Alarm information in BCD. The Command Register (Register B) contains data in binary.
