Battery-Backed-Up RAM and Clock
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Battery-Backed-Up RAM and Clock
An M48T58 RAM and clock chip is used on the MVME167P. This chip
provides a time-of-day clock, oscillator, crystal, power fail detection,
memory write protection, 8KB of RAM, and a battery in one 28-pin
package. The clock provides seconds, minutes, hours, day, date, month,
and year in BCD 24-hour format. Corrections for 28-, 29- (leap year), and
30-day months are made automatically. No interrupts are generated by the
clock. Although the M48T58 is an 8-bit device, the interface provided by
the PCCchip2 ASIC supports 8-, 16-, and 32-bit accesses to the M48T58.
Refer to the PCCchip2 description in the MVME1X7P Single Board
Computers Programmer’s Reference Guide and to the M48T58 data sheet
for detailed programming guidance and battery life information.
VMEbus Interface and VMEchip2
The VMEchip2 ASIC provides the local-bus-to-VMEbus interface, the
VMEbus-to-local-bus interface, and the DMA controller functions of the
local VMEbus. The VMEchip2 also provides the VMEbus system
controller functions.
Refer to the VMEchip2 description in the MVME1X7P Single Board
Computers Programmer’s Reference Guide for detailed programming
information.
I/O Interfaces
The MVME167P provides onboard I/O for many system applications. The
I/O functions include serial ports, printer port, Ethernet transceiver
interface, and 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 standard baud rates (110 to 38.4K
