GE Solar 8000M/i Service Manual page 33

2026265-075C
Equipment overview: Theory of operation
Memory subsystem
The processor PCB provides the memory resources necessary for code
storage and execution, and nonvolatile and configuration data storage by
providing the following:
FLASH Memory for Boot Code, Main Code and Parametric (TMSS)
Storage Memory,
DRAM Memory for Code Execution and Volatile Data Storage, and,
SRAM Memory that is battery backed for Nonvolatile Data Storage.
EEPROM Memory for network configuration data.
The memory subsystem utilizes the memory controller facility of the
MPC860. This allows for the addresses, strobe generation and wait
stating to be under software control.
Peripheral set
Clock Source – The central clock source for the processor PCB is a
crystal oscillator with a frequency of 14.7456 MHz.
Power monitor, watchdog and battery switch – The MAX793
provides the following facilities:
Power-on reset
Battery switchover
Battery charge level indication (battery OK)
Power going away indication (Low Line)
SRAM chip select gating
Manual reset input
Watchdog facility
Real time clock – The Epson RTC-8593AA is the Real Time Clock
(RTC) used. It is an I2C RTC with an internal crystal and can operate
with a supply voltage of +3.3V. The storage of the year will have to be
done in another location since this RTC has only 2 bits for storage of the
year. The RTC must be battery backed to insure that the time is
continued to be kept during power down periods. The I2C address for the
RTC is "1011xxxx".
Serial EEPROM – The serial EEPROM used is a Xicor X24165. The
X24165 is a 16k bit part organized as 2k x 8, I2C compatible and a +3.3V
part. The data stored in the EEPROM would be the Ethernet Address, IP
Address, Software level, product type, year and Power-Applied
Indication. The I2C address for the EEPROM is "1010001x".
NOTE
The serial EEPROM on the Solar 8000M/i processor PCB is not
removable.
Audio tone generation and output amplifier – The Solar 8000M/i
processor PCB provides audio output for alarm and parameter tones.
Solar 8000M/i patient monitor 2-17