Publication No. SBC329-HRM/1
Functional Description 61
5.11.1
RS422/RS485 Mode
The mode of operation for COM2 (i.e. RS232/RS422/RS485) can be configured in the
BIOS, by selecting the relevant option in the EEPROM DIP switch, which is
accessible through the BIOS setup screen. By default, this is set to RS232.
COM2 supports RS485 Auto Direction Control, which automatically enables the
RS485 transceiver when a character is ready to be transmitted. Alternatively, when in
RS422 mode, software must set the RTS signal high by writing to the appropriate
UART register, to enable the transceiver. Again, this configuration is accessible in the
BIOS set up screen.
CAUTION
Take care when connecting RS422/RS485 receivers to either COM port. The default mode of
operation is RS232 which could cause damage to an RS422/RS485 receiver because of its high
operating voltage. Ensure that the correct mode is set in the BIOS before connecting hardware.
5.12 SATA
The SBC329 provides up to four SATA interfaces. Three may be routed to the VPX
backplane connectors for connection to off-board peripherals such as hard disk
drives or CD/DVD drives, and the remaining port is connected directly to the
on-board SSD device.
All backplane ports can operate at SATA Revision 3.0 data transfer rates (up to
6 Gb/second). The operating mode of the controller can be set in the BIOS setup
menus by selecting the SATA configuration menu in the Advanced tab (see
). The default setting is SATA 3 Gb/second.
NOTE
Due to limitations in the VPX backplane bandwidth capability, the use of signal re-drivers at the
system level may be required to guarantee SATA 6 Gb/second operation. The RTMs for the
SBC329 (VPX3UX301 and VPX3UX601) include re-drivers on all available SATA ports.
On the SBC329, one SATA port is always available, whereas the other two are only
available with the correct build variant. The following table summarizes each port
connection and controller assignment:
Table 5-11 SATA Signal Availability
PCH Port
Number
Build Variant
Availability
SATAx_TXP
SATAx_TXN SATAx_RXP SATAx_RXN
0
All variants
P1/D9
P1/E9
P1/A9
P1/B9
1
SBC329-xxxxx1xxx or
SBC329-xxxxx2xxx
P2/D5
P2/E5
P1/A5
P1/B5
2
SBC329-xxxxx1xxx or
SBC329-xxxxx2xxx
P2/E6
P2/F6
P1/B6
P1/C6
3
All variants
On-board SSD
A single LED (
) on the rear of the PWB shows activity on any of the SATA
ports.