Motorola MCPN750A, IH5 manual ISA Bus Devices, Serial Eeprom, Asynchronous Serial Ports

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Functional Description

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 I2C port in the upper Falcon memory controller chip.

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