Smiths Medical Medfusion 3000 Series, Technical & Service Manual

Page: 40 / 184

Theory of Operation
34
40-5648-51B
Signal name Processor port Description
reset* Reset Provided from the system-reset circuit located in the Power Control
Logic section of the Main PCB.
VRH 4.096V A/D reference.
AVDD, AVSS,
and VRL
The main processor’s analog to digital conversion supply and refer -
ence pins.
Flash memory, U22
Flash program memory is 512 K × 8. It is addressed as
16 pages of 32 K × 8 each.
Flash memory can be reprogrammed within the system .
Software upgrade method for programming flash
memory
The re-programmable feature of Flash Memory provides
for software upgrades. The pump is placed in a special
Biomed mode which allows reprogramming of the soft -
ware through the infrared serial port.
Static random access memory, U17
Static RAM is 32 K × 8 bit.
Serial EEPROM, U2 and U4
The serial EEPROMs are used for storing manufactur -
ing, calibration, configuration, libraries, the history
event log, the PharmGuard
®
Safety Data, and the service
data requiring non-volatile random access.
Medfusion™ 3000 series pumps may have two 8K x 8
bit EEPROMs, two 16K x 8 EEPROMs, or two 32K x 8
EEPROMs.
Time of day, U8
The time of day, including calendar, is maintained by the
RS5C316B which is continually powered as long as AC,
external DC voltage, or internal battery is present, or the
super capacitor is charged.
Infrared transceiver
An IR transceiver, located on the Interconnect board,
provides an electrically isolated asynchronous serial
communication link between the pump and an external
system. The infrared link is intended for short distances
of less than a few inches.