Intel SR6850HW4 - Manual (Page 93)

Intel® Server Platform SR6850HW4 TPS SCSI Backplane Board
Revision 1.0
Intel order number D23151-001
81
Signal Type Driver Name and Description
LVD_IO_[P, N] I/O LVD hs SCSI bus I/O phase. Driven by the target, these pins control the
direction of data transfer on the SCSI bus. When asserted, this signal
indicates input to the initiator. When not asserted, this signal indicates
output from the initiator.
GND I/O PWR Ground. Provide secondary ground reference.
7.3.5 SCA2 80-pin Drive Connectors
The SCA2 connector carries power and signal between the SCSI Backplane Boardboard and
hot-swap SCSI hard disk drives. The LVD SCSI bus signals are driven by either the Server
Board Set SE8500HW4 Mainboard SCSI controller, the LVD transceiver, or the hot-swap SCSI
hard disk drives. Table 47 provides a description of each signal on the SCSI connectors.
Table 47. .LVD SCSI Bus Signals
Signal Type Driver Name and Description
LVD_DB[15..0]_[P, N] I/O LVD hs SCSI data bus. Along with the DBP[1/0][P/N] pins they form the bi-
directional SCSI data bus.
LVD_DBP_[P, N]
LVD_DBP1_[P, N] I/O LVD hs SCSI data parity. Support parity on the SCSI bus.
DBP[P/N] supports parity for data [7..0]
DBP1[P/N] supports parity for data [15..8]
DIFFSENSE I Analog Differential sense. Monitor the DIFFSENSE signal from the
terminator. The voltage level determines the operating mode of the
target devices on the SCSI bus. If the voltage on the DIFFSENSE
signal is from –0.35V to +0.5V the mode will be SE. If it is from
+0.7V to 1.9V the mode will be LVD.
LVD_ATN_[P, N] I/O LVD hs SCSI bus attention. Asserted by a SCSI device in initiator mode to
alert the target that the initiator has a message to transfer.
LVD_BSY_[P, N] I/O LVD hs SCSI bus busy. In SE mode, these pins are bi-directional and are
asserted to gain use of the SCSI bus and to indicate that that SCSI
bus is in use.
LVD_ACK_[P, N] I/O LVD hs SCSI bus acknowledge. Asserted by a SCSI device in initiator mode
to acknowledge the target’s request for a data transfer.
LVD_RST_[P, N] I/O LVD hs SCSI bus reset. In SE mode, these pins are bi-directional and are
asserted when all the SCSI devices attached to the SCSI bus need
to be reset.
LVD_MSG_[P, N] I/O LVD hs SCSI bus message phase. Asserted by a SCSI device in target
mode to indicate the Message In or Message Out phase.
LVD_SEL_[P, N] I/O LVD hs SCSI bus select. In SE mode, these pins are bi-directional and are
asserted by the controller when attempting to select or reselect a
SCSI device.
LVD_CD_[P, N] I/O LVD hs SCSI bus control/data phase. Asserted or de-asserted by a SCSI
device in target mode to indicate that control or data information is
being transferred over the SCSI bus
LVD_REQ_[P, N] I/O LVD hs SCSI bus request. Asserted by a SCSI device in target mode to
indicate that the target is requesting a data transfer over the SCSI
bus.
LVD_IO_[P, N] I/O LVD hs SCSI bus I/O phase. Asserted by a SCSI device in target mode to
indicate the direction of data movement on the SCSI bus between
the target and the initiator.