Intel D95738-001US Manuale Utente

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Product Description 
 23
 
1.7 
Parallel IDE Controller 
The Parallel ATA IDE controller has one bus-mastering Parallel ATA IDE interface.  The 
Parallel ATA IDE interface supports the following modes: 
•  Programmed I/O (PIO):  processor controls data transfer. 
•  8237-style DMA:  DMA offloads the processor, supporting transfer rates of up to 
16 MB/sec. 
•  Ultra DMA:  DMA protocol on IDE bus supporting host and target throttling and 
transfer rates of up to 33 MB/sec. 
•  ATA-66:  DMA protocol on IDE bus supporting host and target throttling and 
transfer rates of up to 66 MB/sec.  ATA-66 protocol is similar to Ultra DMA and is 
device driver compatible. 
•  ATA-100:  DMA protocol on IDE bus allows host and target throttling.  The ATA-100 
logic can achieve read transfer rates up to 100 MB/sec and write transfer rates up 
to 88 MB/sec.   
 
NOTE 
ATA-66 and ATA-100 are faster timings and require a specialized cable to reduce 
reflections, noise, and inductive coupling. 
The Parallel ATA IDE interface also supports ATAPI devices (such as CD-ROM drives) 
and ATA devices.  The BIOS supports Logical Block Addressing (LBA) and Extended 
Cylinder Head Sector (ECHS) translation modes.  The drive reports the transfer rate 
and translation mode to the BIOS.  
 
For information about  
Refer to 
The location of the Parallel ATA IDE connector 
1.8 
Real-Time Clock Subsystem 
A coin-cell battery (CR2032) powers the real-time clock and CMOS memory.  When 
the computer is not plugged into a wall socket, the battery has an estimated life of 
three years.  When the computer is plugged in, the standby current from the power 
supply extends the life of the battery.  The clock is accurate to ± 13 minutes/year at 
25 ºC with 3.3 VSB applied. 
 
NOTE 
If the battery and AC power fail, custom defaults, if previously saved, will be loaded 
into CMOS RAM at power-on. 
When the voltage drops below a certain level, the BIOS Setup program settings stored 
in CMOS RAM (for example, the date and time) might not be accurate.  Replace the 
battery with an equivalent one.  Figure 1 on page 12 shows the location of the battery.