MVME197LE Functional Description

format. Corrections for 28-, 29-, (leap year) and 30-day months are automatically made. No interrupts are generated by the clock. The MK48T08 is an 8-bit device; however the interface provided by the PCCchip2 supports 8-, 16-, and 32-bit accesses to the MK48T08. Refer to the PCCchip2 chapter in the MVME197LE, MVME197DP, and MVME197SP Single Board Computers Programmer’s Reference Guide and to the MK48T08 data sheet for detailed

programming information.

VMEbus Interface

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The local peripheral bus to VMEbus interface, the VMEbus to local peripheral bus interface, and the local-VMEbus DMA controller functions on the MVME197LE are provided by the VMEchip2. The VMEchip2 can also provide the VMEbus system controller functions. Refer to the VMEchip2 chapter in the MVME197LE, MVME197DP, and MVME197SP Single Board Computers Programmer’s Reference Guide for detailed programming information.

I/O Interfaces

The MVME197LE provides onboard I/O for many system applications. The I/O functions include serial ports, a printer port, an Ethernet transceiver interface, and a SCSI mass storage interface.

Serial Port Interface

The CD2401 serial controller chip (SCC) is used to implement the four serial ports. The serial ports support the standard baud rates (110 to 38.4K baud). Serial port 4 also supports synchronous modes of operation.

The four serial ports are different functionally because of the limited number of pins on the I/O connector.

Serial port 1 is a minimum function asynchronous port. It uses RXD, CTS, TXD, and RTS.

Serial ports 2 and 3 are full function asynchronous ports. They use RXD, CTS, DCD, TXD, RTS, and DTR.

Serial port 4 is a full function asynchronous or synchronous port. It can operate at synchronous bit rates up to 64k bits per second. It uses RXD, CTS, DCD, RTS, and DTR. It also interfaces to the synchronous clock signal lines.

Refer to the MVME197LE, MVME197DP, and MVME197SP Single Board Computers Programmer’s Reference Guide for drawings of the serial port interface connections.

MVME197LE/D2

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Motorola MVME197LE user manual VMEbus Interface, Interfaces, Serial Port Interface