![background image](http://html1.mh-extra.com/html/ibm/thinkpad-560z/thinkpad-560z_supplementary-manual_3424226040.webp)
Bit 0
If set to 1, this bit enables the daylight-saving-time mode.
If set to 0, this bit disables the daylight-saving-time mode,
and the clock reverts to standard time. The system
initializes this bit to 0.
Status Register C (X
'
00C
'
)
Figure
2-18. Status Register C (X
'
00C
'
)
Bit
Function
7
Interrupt request flag
6
Periodic interrupt flag
5
Alarm interrupt flag
4
Update-ended interrupt flag
3–0
Reserved
Note: Interrupts are enabled by bits 6, 5, and 4 in status register B.
Bit 7
If set to 1, this bit indicates that an interrupt has
occurred; bits 6, 5, and 4 indicate the type of interrupt.
Bit 6
If set to 1, this bit indicates that a periodic interrupt has
occurred.
Bit 5
If set to 1, this bit indicates that an alarm interrupt has
occurred.
Bit 4
If set to 1, this bit indicates that an update-ended
interrupt has occurred.
Bits 3–0
These bits are reserved.
Status Register D (X
'
00D
'
)
Figure
2-19. Status Register D (X
'
00D
'
)
Bit
Function
7
Valid RAM
6–0
Reserved
Bit 7
This read-only bit monitors the internal battery. If set to
1, this bit indicates that the real-time clock has power. If
set to 0, it indicates that the real-time clock has lost
power and the data in CMOS is no longer valid.
Bits 6–0
These bits are reserved.
2-22
ThinkPad 560Z System Board