Samsung WA31273A Technical Manual page 67

6-4-4-9-4 LBA Supported
Bit 9 of word 49 is used to indicate if the device supports LBA mode addressing. If this
bit is set, words 60-61 shall be valid.
6-4-4-9-5 DMA Supported
Bit 8 of word 49 is used to indicate of the device supports the READ/WRITE DMA
commands.
6-4-4-10 Word 51 : PIO data transfer cycle timing mode
The PIO transfer timing for each ATA device falls into categories which have unique
parametric timing specifications. To determine the proper device timing category,
compare the Cycle Time specified in figure 10 with the contents of this field. The value
returned in Bits 15-8 should fall into one of the mode 0 through mode 4 categories
specified in figure 10, and if it does not, then Mode 0 shall be used to serve as the default
timing. Note: For backwards compatibility with BIOSs written before Word 64 was
defined for advanced modes, a device reports in Word 51 the highest original PIO mode
(i.e. PIO mode 0, 1, 2, 3 or 4) it can support.
6-4-4-11 Word 52 : Single Word DMA data transfer cycle timing mode
The DMA transfer timing for each ATA device falls into categories which have unique
parametric timing specifications. To determine the proper device timing category,
compare the Cycle Time specified in figure 11 with the contents of this field. The value
returned in Bits 15-8 should fall into one of the categories specified in figure 11 (i.e. 0, 1
or 2), and if it does not, then Mode 0 shall be used to serve as the default timing.
6-4-4-12 Word 53 : Field Validity
If bit 0 of word 53 is set, then the values reported in words 54 through 58 are valid. If
this bit is cleared, the values reported in words 54 through 58 may be valid. If bit 1 of
word 53 is set, then the values reported in words 64 through 70 are valid. If this bit is
cleared, the values reported in words 64-70 are not valid. Any device which supports
PIO modes 3 or above, or supports Multi-word DMA Mode 1 or above, shall set bit 1 of
word 53 and support the fields contained in words 64 through 70.
6-4-4-13 Word 54 : Number of current logical cylinders
The number of user-addressable logical cylinders in the current translation mode.
6-4-4-14 Word 53 : Number of current logical heads
The number of user-addressable logical heads per logical cylinder in the current
translation mode.
WA31273A / WA32543A / WA33203A / WA32163A / WA31083A / WA32162A 6-23
AT INTERFACE and ATA COMMANDS