Acer AcerNote 970 Service Manual page 37

Table 1- 13 PMU Timers List
Item
System activities
and timer retriggers
Detective hardware
change
1.5.7.2 Component activities in power saving mode
•
Hard disk
The hard disk is fully power managed. This means that when the hard disk is not in use, the
hard disk is powered off. The following pins are dedicated toward the management of power
on the hard disk.
1. IDE controller clock enable [pin-32(KB5_IDECLKEN) of KBC]. Disabled only when both
the HDD and the CD-ROM are not in use (timed-out). This pin stops the clock to the IDE
controller chip. This chip is static and has no internal power down capabilities.
2. HDD buffer enable [pin-36(KB5_HDDBEN#) of KBC]. When the hard disk is powered off,
the buffer disconnects the off-state drive from the still operative controller. The buffer is
sequenced to disable the interface before the drive is powered down and to re-enable the
interface after the drive is powered up.
3. HDD power enable[pin-42(SM5_HDPON) of SMC ]. This pin turns the power on/off for
the hard disk only.
4. HDD reset[pin-40(SM5_HDRST#) of SMC]. This pin provides the reset to the drive when
the drive is newly powered up. The reset pin is asserted when the drive is first powered
up, then the reset is removed after the drive is powered up and before the interface is
enabled.
System activities
−
Power off either or both FDD and CD-ROM. Tri-state FDD and CD-ROM
interfaces and stop IDE controller clock.
Timer retriggers
−
The I/O access to 3F2, 3F4, 3F5, 3F7, 170-7, 376 will retrigger the timer.
1. The pin-89 (CK3_IDECLK) of PCI0643 is tri-stated, IDE controller clock is
stopped.
2. The KB5_CDBEN# signal on pin-1, 13 of S3384(UX1 and UX2, IDE interface
buffer), and pin-13 of S3384 (U22, IDE interface buffer) are from L to H. CD-
ROM buffer is disabled.
3. The pin-30, 31, 32 (CD/FDDVCC) of CN11 FDD/CD connector is from H to L,
the FDD/CD-ROM is powered off.
Descriptions