9: Processor Board
PRC1099A-MS
9-3
GPI1 through GPI3 are for external interrupt sources while address lines A1
through A20 and data lines D0 through D15 communicate with the external
EPROM, RAM, and analog converter system.
9.1.2
EPROM Program Storage
EPROM chips U2 and U3 provide storage for the main software operating
program.
9.1.3
RAM Program Storage
RAM chips U4 and U5 provide storage for all the channel frequency data,
display data, and memory tuner information.
9.1.4
Clock Oscillator Circuit
The clock oscillator is internal within the processor, except for the external
crystal Y1, and capacitors C48 and C49.
9.1.5
Processor Controller
Controller U9 provides three functions. As a reset controller it has a voltage
detector that monitors the +5V line. It generates a reset output to hold the
processor’s reset line low whenever the +5V line is below 4.65 VDC. An
internal monostable multivibrator holds the reset line low for
200 milliseconds after the +5V line rises above 4.65 VDC. This prevents
repeated toggling of the reset line.
U9 is also a power failure detector that issues a non-maskable interrupt to the
processor whenever a power failure occurs. This lets the processor power
down in the correct state before data is lost.
U9 also functions as memory backup preserving the contents of RAM
memory storage. This is storage for frequency program information and must
be preserved at all times. When a power failure is detected, the lithium battery
is automatically switched in to preserve the RAM memory data.
9.1.6
Memory Backup Circuit
The memory backup power circuit includes memory backup battery BT1,
current limiting resistor R22, and reverse protection diode D3. This battery
provides backup power for the RAM chip to prevent settings loss.
9.1.7
RS-232 I/O Circuit
RS-232 chip U8 communicates with the front panel communications port. U8
has an on-board capacitor charge pump for generating the -10 VDC and
+10 VDC necessary for RS232 communications. This circuit can easily
handle baud rates up to 9600 baud. It also can be put into a low power idle
mode for low power consumption.
Содержание PRC1099A
Страница 4: ......
Страница 8: ......
Страница 35: ......
Страница 49: ...3 Audio Filter Board 3 14 PRC1099A MS Figure 3 2 Audio Filter Board Component Locations 738221 Rev J ...
Страница 65: ......
Страница 71: ...4 1650 kHz IF Board 4 6 PRC1099A MS Figure 4 2 1650 kHz IF Board Component Locations 738028 Rev D ...
Страница 76: ......
Страница 86: ...5 Mixer Board 5 10 PRC1099A MS Figure 5 4 Mixer Board Component Locations 738217 Rev H ...
Страница 97: ......
Страница 103: ...6 Power Amplifier Board 6 6 PRC1099A MS Figure 6 2 Power Amplifier Board Component Locations 738617 Rev C ...
Страница 117: ...7 Antenna Tuner Board PRC1099A MS 7 9 Figure 7 2 Antenna Tuner Driver Board Component Locations 738346 Rev B ...
Страница 118: ...7 Antenna Tuner Board 7 10 PRC1099A MS Figure 7 3 Antenna Tuner Board Component Locations 738027 Rev D ...
Страница 125: ......
Страница 131: ...8 Synthesizer Board 8 6 PRC1099A MS Figure 8 2 Synthesizer Board Component Locations 738025 Rev A ...
Страница 163: ...9 Processor Board 9 14 PRC1099A MS Figure 9 2 Processor Board Component Locations 738218 Rev B ...
Страница 178: ...10 Display Board 10 8 PRC1099A MS Figure 10 1 Display Board Component Location Diagram 738220 Rev G ...
Страница 181: ......
Страница 185: ...11 Junction Board 11 4 PRC1099A MS Figure 11 1 Junction Board Component Locations 738222 Rev F ...
Страница 200: ......
Страница 207: ...13 Internal Options PRC1099A MS 13 7 Figure 13 3 ALE Board Component Locations 1 of 2 738215 Rev B ...
Страница 208: ...13 Internal Options 13 8 PRC1099A MS Figure 13 4 ALE Board Component Locations 2 of 2 738215 Rev B ...
Страница 241: ......
Страница 247: ...Index 6 T Technical specifications 1 2 Transmit path 2 4 U USB 1 4 see also Modulation modes USB LSB mode V VSWR 1 4 ...