Nellcor OxiMax N 5500 Service Manual page 91

System Processing Description
l Sound unit : consists of 8bit PIC micom, 2-channel amplifiers and speaker.
PIC 16C63A
l Communication unit : 4-channel UART
S3C44B0X System BUS
l GUI (graphic user interface) unit : consists of TFT LCD, inverter for backlit and
internal video controller.
TFT LCD
INVERTER
FOR
BACKLIGHT
l Thermal Printer unit : prints data records.
Asyncronous Serial Communication with Communication UNIT
84
Frequency
PWM OUT
to Voltage
Conversion
Sound Pulse
Sound Pulse
Frequency
PWM OUT
to Voltage
Conversion
Figure 15. Sound Unit Block Diagram
UART
Figure 16. Communication Unit Block Diagram
LCD
LEVEL
Control
CONVERSION
Signal
&
DAMPING R
BYPASS C
Figure 17. GUI Unit Block Diagram
Error Signal
Figure 18. Thermal Printer Unit Block Diagram
N5500 Service Manual
Volume
Control
Audio AMP 1
Audio AMP 2
Volume
Control
Asyncronous Serial Communication with NIBP UNIT
Asyncronous Serial Communication with Analog Control Unit
Asyncronous Serial Communication with TCP/IP UNIT
Asyncronous Serial Communication with Printer UNIT
LCD
LCD Controller
Control
Signal
SED1385F0A
with
VIDEO MEMORY
Thermal Printer
Alarm
Speaker
Pulse Tone
Speaker
S3C44B0X System BUS