Reference Manual

Flex CPU Piggyback Board Hardware Reference
Board Configuration 3
BOARD CONFIGURATION
Non-Turbo CPU Base Configuration
When assembled for a non-Turbo CPU, the DSP IC in U1 of the Flex CPU board contains all of the
memory required for operation. Therefore, there are no ICs installed in the locations for external RAM:
U11, U12, U13, U14, U15, and U16.
The CPU is available in several speed options: 40 MHz (Option 5AF), 80 MHz (Option 5CF), and 160
MHz (Option 5EF). The maximum frequency of operation is indicated with a sticker on the CPU in U1.
When the Flex CPU is built for ISA-bus or VME-bus baseboards, the P3 connector consists of a 36-pin
header on the solder side for direct connection to the baseboard, and a 10-pin header on the component
side for cable connection of the extra signals required for dual-ported RAM interface. When the Flex
CPU is built for PCI-bus baseboards the P3 connector consists only of a 56-pin header on the solder side
for direct connection of all signals to the baseboard.
Non-Turbo CPU Further Options
The Option 16 battery-backed parameter RAM provides a bank of non-volatile memory for the controller.
Its key components are RAM ICs in U17, U18, and U19, and a battery in BT1
Turbo CPU Base Configuration
When assembled for a Turbo CPU section, the Flex CPU board contains external RAM ICs in locations
U11, U12, U13, U14, U15, U16. With the standard memory configuration (Option 5x0), these ICs fill the
smaller footprint in these locations, leaving an open pin on the board on each end of each side.
When the Flex CPU is built for ISA-bus or VME-bus baseboards, the P3 connector consists of a 36-pin
header on the solder side for direct connection to the baseboard, and a 10-pin header on the component
side for cable connection of the extra signals required for dual-ported RAM interface. When the Flex
CPU is built for PCI-bus baseboards the P3 connector consists only of a 56-pin header on the solder side
for direct connection of all signals to the baseboard.
Turbo CPU Further Options
If an expanded memory configuration (Option 5x3) is ordered, larger RAM ICs are installed in locations
U11, U12, U13, U14, U15, U16, occupying the full footprints in these locations
If the Option 9T auxiliary serial port is ordered for the Turbo PMAC controller, an RS-232 serial port is
provided on the CPU board to supplement the serial port on the baseboard. The key components are ICs
in U28 and U29, and the connector J8.
The Option 16A battery-backed parameter RAM provides a bank of non-volatile memory for the
controller. Its key components are RAM ICs in U17, U18, and U19, and a battery in BT1