Motorola MCPN750A, Installation And Use Manual

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Functional Description
6
ISA Bus Devices
The MCPN750A contains a local ISA bus to provide an interface to ISA
compatible devices. The following devices are located on the ISA bus:
❏
Four asynchronous serial ports
❏
Real-Time Clock & NVRAM & Watchdog Timer
❏
Configuration and Status Registers
Asynchronous Serial Ports
The MCPN750A SBC contains four 16C550C UART devices. Serial port
1 (COM1) is wired as an RS-232 interface to an RJ45 connector on the
front panel. The Serial 1 port TTL signals are also routed to J3 for
transition module I/O. A jumper on the Transition Module enables the
COM1 port either on the MCPN750A or the Transition Module. The other
three serial port TTL signals are routed to the J3 I/O connector only. To
save pins on the J3 connector, the all Serial Port control lines routed
through J3 are serialized using the IOMUX PLD.
Configuration and Status Registers
The MCPN750A base board contains several registers used to provide
configuration and status information about the board. These registers are
implemented with discrete logic or in PLDs. Refer to the MCPN750A
CompactPCI Single Board Computer Programmer’s Reference Guide
(MCPN750A/PG) for details on these registers.
Serial EEPROM
The MCPN750A base board contains a 512 x 8 Serial EEPROM. The
Serial EEPROM provides for vital product data storage of the board
configuration information and the SPD memory configuration
information. The Serial EEPROM is accessed through the I
2
C port in the
upper Falcon memory controller chip.