User's Manual

Turbo PMAC2 PCI Hardware Reference Manual
Hardware Setup 5
HARDWARE SETUP
Piggyback Turbo CPU Board Jumper Configuration
Watchdog Timer Jumper
Jumper E1 on the Turbo CPU board must be OFF for the watchdog timer to operate. This is a very
important safety feature, so it is vital that this jumper be OFF in normal operation. E1 should only be put
ON to debug problems with the watchdog timer circuit.
Dual-Ported RAM Source Jumper
On Turbo CPU boards with revision suffixes – 10A and newer, jumper E2 must connect pins 1 and 2 to
access dual-ported RAM (addresses $06xxxx) from the baseboard. If using the Option 2 DPRAM on the
baseboard, jumper E2 must be in this setting.
Jumper E2 must connect pins 2 and 3 to access dual-ported RAM (addresses $06xxxx) through the JEXP
expansion port. If using the DPRAM on an external accessory board, jumper E2 must be in this setting.
On Turbo CPU boards with revision suffixes – 109 and older, there is no jumper for this purpose, and the
boards can access DPRAM from either source, but with less robust buffering.
Power-Up State Jumpers
Jumper E4 on the Turbo CPU board must be OFF, jumper E5 must be ON, and jumper E6 must be ON in
order for the CPU to copy the firmware from flash memory into active RAM on power-up/reset. This is
necessary for normal operation of the card. (Other settings are for factory use only.)
Firmware Load Jumper
If jumper E7 on the CPU board is ON during power-up/reset, the board comes up in bootstrap mode,
which permits the loading of new firmware into the flash-memory IC on the board. When the PMAC
Executive program tries to establish communications with a board in this mode, it will detect that the
board is in bootstrap mode automatically and ask what file to download as the new firmware.
Jumper E7 must be OFF during power-up/reset for the board to come up in normal operational mode.
Base Board Jumper Configuration
Servo and Phase Clock Direction Control
Jumper E1 should be OFF if the board is to use its own internally generated phase and servo clock
signals. In this case, these signals are output on spare pins on the J5A RS-422 serial-port connector,
where they can be used by other PMAC controllers set up to take external phase and servo clock signals.
Jumper E1 should be ON if the board is to use externally generated phase and servo clock signals brought
in on the J5A RS-422 serial port connector. In this case, the clock signals are generated by another
PMAC controller and output on its serial port connector. Commonly, serial communications are also
shared over a multi-drop RS-422 cable, with software addressing of the cards matching the I0 serial card
number for each controller. Alternately, the phase and servo clock signals can come from clock signals
involved in the process.
If E1 is ON for external phase and clock signals, and these clock signals are not brought in on the serial
port connector, the watchdog timer will trip almost immediately and shut down the board.
In order to change the state of the card between use of internal clock and use of external clock, the card
must be re-initialized – either powered up with jumper E3 ON, or given the $$$*** command – with
jumper E1 in the new state. Before the card is reset again, a SAVE command must be issued to store the
new internal settings.