6 fans, 7 internal logic signals – Intel SR6850HW4 User Manual
Page 94

SCSI Backplane Board Intel® Server Platform SR6850HW4 TPS
Revision
1.0
Intel order number D23151-001
82
Signal
Type
Driver
Name and Description
SCSI_ID
O
GND/OPEN
SCSI ID. Sets internal SCSI ID depending on slot. Drive 1 has SCSI
address 0. Drive 2 has SCSI address 1 and so on.
SCSI_MATED_L [1-5]
I/O
TTL
SCSI MATED. Determine if SCSI is present and has proper contact.
GND I/O
PWR
Ground.
Provide
secondary ground reference.
+12V
O
PWR
+12 Volt supply. Max 1A of continuous current/6A peak current.
+5V
O
PWR
+5 Volt supply. Max 1.4A of continuous current/6A peak current.
7.3.6 Fans
Each fan has an integral amber LED with a grounded cathode. This provides a small current to
a transistor that drives the FAN[10..1]_PRES signal. This signal is read by server management
through U2P1, and the PCA9555 I
2
C Port. Server management can also use U2P1 to turn on a
FAN[10..1]_LED signal. FET drivers boost the current through the LED to brighten it.
The FAN_PWM signal from the Mainboard controls the fan speed. The FAN[10..1]_TACH signal
is shaped by an FET buffer and driven to the Mainboard as FAN[10..1]_TACH_BUFF for
determination of fan speed.
7.3.7 Internal Logic Signals
Table 48 is a summary of the signals that route between logic on the SCSI Backplane Board.
Table 48. Internal Logic Signals
Signal
Type
Driver
Name and Description
Clks
CLK_10MHz
O
CMOS
10-MHz clock that is used by the GEM359 and PLD.
ADDR<16..0>
O
CMOS
Address/bus. Address bus for the FLASH.
PROM_VPP_L
O
CMOS
FLASH PROGRAM VOLTAGE ENABLE. Driven by the
GEM359 to all FLASH to be programmed.
PROM_OE_L
O
CMOS
FLASH output enable. Driven by the GEM359 to enable the
FLASH for writing data on the bus.
PROM_CE_L
O
CMOS
FLASH output enable. Driven by the PLD to enable the
FLASH.
GEM359 Logic Control
PROM_WE_L
I
CMOS
FLASH chip enable. Driven by the GEM359 to enable
writing to the FLASH.
KCK_5V_L [1-10]
O
Analog
5 Volt kick start. Primes 5 Volt FET to start delivering power
to a drive.
KCK_12V_L [1-
10]
O
Analog
12 Volt kick start. Primes 12 Volt FET, to start delivering
power to a drive.
FLT_5V_L [1-10]
I
CMOS
5 Volt hot-swap fault. Indicates greater than 5A of current
drawn from 5V rail.
FLT_12V_L [1-10] I
CMOS
12 Volt hot-swap fault. Indicates greater than 5A of current
drawn from 12V rail.
STP_5V_L[1-10] I
Analog 5
Volt stop. Stops 5 Volt FET from delivering power to a
drive.
SCSI Power Control
STP_12V_L[1-10] I
Analog 12
Volt stop. Stops 12 Volt FET from delivering power to a
drive.