User's Manual

PMAC2 PCI Lite Hardware Reference Manual – Preliminary Documentation
6 Hardware Setup
Serial Port Selection Jumper
Jumpers E17 and E18 control which serial-port connector is used. If E17 and E18 connect their pins 1
and 2, the 10-pin RS-232 port connector J5 is used. If E17 and E18 connect their pins 2 and 3, the 26-pin
RS-422 port connector J5A is used. The RS-422 port must be used if several cards are to be daisy-
chained together on a single multi-drop cable.
Output Disable State Jumpers
Jumpers E111 through E114 control the hardware state of the digital command output signals for each
channel when the amplifier enable signal for that channel is in the disable state (false). Jumper E11n (n =
1 to 4) controls the output signals for channel n on the board.
If E11n is off (default), the command output signals for channel n are still active when the amplifier
enable signal is in the disable state. The Turbo PMAC software should be commanding a net zero
command to be output on these signals, and the amplifier-enable signal should be used by the amplifier so
that no command output will cause action if it is receiving a disable signal. The Off setting should be
used when DAC output format is selected for the channel.
If E11n is on, the command output signals for channel n are tri-stated when the amplifier-enable signal is
in the disable state. This setting is used only with direct-PWM power-block amplifiers that do not use
amplifier enable to gate the PWM signals, and in which the zero-command format of 50% top on-time,
and 50% bottom on-time cannot be tolerated in the disable state.
Amplifier Enable / EQU Jumper
WARNING
The jumper setting must match the type of driver IC, or damage to the IC will
result.
Jumpers E11 and E12 control the polarity of the AENA and EQU lines. Their default setting is 1 to 2
which applies GND to pin 10 of U93 AENA/EQUn driver IC. This is used for 74ACT563, 74ACT573,
and ULN2803 model sinking chips.
To source the AENA and EQU lines, apply +V to pin 10 of U93, jump pin 2 to 3. This is used for
UDN2891 model sourcing chip.
Note:
If using ULN2803 or UDN2981 model chips, be sure to plug pin 1 of chip into
socket starting at pin 2.