Emerson MVME7100 manual 4.4 I2C Serial Interface and Devices, System Memory

I2C Serial Interface and Devices Functional Description

The MVME7100 supports the power-on reset (POR) pin sampling method for processor reset configuration. The states of the various configuration pins on the processor are sampled when reset is de-asserted to determine the desired operating modes. Combinations of pull-up and pull-down resistors are used to set the options. Some options are fixed and some are selectable at build time by installing the proper pull-up/pull-down resistor. Refer to the MC864xD reference manual, listed in Appendix B, Related Documentation, Manufacturers’ Documents on page 101 for additional details and/or programming information.

4.4I2C Serial Interface and Devices

The MVME7100 provides the following on-board I2C serial devices connected to the MC864xD I2C controller 0 interface:

z8 KB serial EEPROM for VPD

zTwo 64 KB serial EEPROMs for user configuration data storage

zTwo 256 byte serial EEPROMs for SPD

zMaxim DS1375 Real Time Clock

zMaxim MAX6649 temperature sensor

z8 KB serial EEPROM on RTM VPD

The RTC implemented on the MVME7100 provides an alarm interrupt routed to the MC864xD PIC through the control PLD. A DS32KHz temperature controlled crystal oscillator provides the RTC clock reference. A battery backup circuit for the RTC is provided on-board.

The Maxim digital temperature sensor measures of temperature of the board and also connects to the temperature diode on the MC864xD. The temperature sensor also provides an alarm interrupt routed to the MC864xD PIC through the control PLD.

The I2C interface is routed to the P2 connector for access to the serial EEPROM located on the transition module. The device address for the transition module serial EEPROM is user selectable using the configuration switches. Refer to Chapter 5, Transition Module for information on the switches.

For programming information, see the MVME7100 Single Board Computer Programmer’s Reference.

4.5System Memory

The MC864xD includes two memory controllers. The MVME7100 supports one bank of memory on each controller. The MVME7100 supports 512 MB, 1 GB and 2 GB DDR2 SDRAMS. This provides memory configurations of 1 GB, 2 GB, and 4 GB. The MVME7100 supports memory speeds up to DDR533.

MVME7100 Single Board Computer Installation and Use (6806800E08A) 69