Western Digital T13/2132-D - Manual (Page 79)

June 23, 2010 T13/2132-D Revision 3
Working Draft Enhanced Disk Drive - 4 (EDD-4) 67
This PSS shall add transport specific information (e.g., header information and CRC) and modify the CDB where
necessary with bus specific information. If the secondary bus is a hot-plug bus such as 1394 or USB, the PSS
shall insert device addresses or EUI-64 as necessary. In the event that a device address changes due to a bus
reset or re-enumeration, the PSS shall connect with the device without generating an error.
8.27.2.2 Formatted Protocol Specific Data
Table 31 defines the format of the data passed in ES:SI (see 8.27.1) to INT 13h FN 50h.
Table 31 — Formatted Protocol Specific Data
Offset Type Description
0 Word Packet length in bytes including this word
2
Byte Information flags
Bit Description
7:6 Data direction.
00 = No data exchanged with device (command only)
01 = Receive data from device
10 = Send data to device
11 = Reset Interface.
5:0 Reserved
3 Byte Bytes in command packet, or zero if no command is to be sent.
4 DWord Pointer to command packet. This field follows the seg:offset address format. This field is
ignored if offset 3 is zero.
8 DWord Number of bytes to transfer following command complete. Shall be a multiple of the sector
size of the media, as returned by Function 48h. If the data direction bits in the flags register
do not indicate a send or receive data command, then this field shall be ignored. Otherwise,
if this value shall be zero, then a zero byte transfer shall occur.
10h DWord Pointer to the start of the data stream to transfer. This field follows the seg:offset address
format.
14 Word Access timeout. Maximum time in milliseconds to wait for command start. Command start
includes sending the command to the devices and waiting for the first data byte to transfer.
If this field contains the value of 0000h, an 80h error (see table 32) shall result.
16 Word Sector timeout increment. The PSS shall divide the amount of data transferred by the
sector size, round up, multiply by this value, and add to the Access Timeout (offset 14), the
maximum result is limited to FFFFh. This shall be the total timeout for the specified CDB.
This value shall be ignored for command-only and bus-reset calls.