Kenwood TK-8100 Service Manual page 29

TK-8100
Control Circuit
The CPU carries out the following tasks:
1) Controls the WIDE, NARROW, TX/RX outputs.
2) Adjusts the AF signal level of the AF filter (IC251) and
turns the filter select compounder on or off.
3) Controls the display unit.
4) Controls the PLL (IC401).
5) Controls the D/A converter (IC161) and adjusts the vol-
ume, modulation and transmission power.
■ Memory Circuit
The transceiver has a 64k-bit EEPROM (IC66). The
EEPROM contains adjustment data. The CPU (IC101) con-
trols the EEPROM through three serial data lines.
■ Display Circuit
The CPU (IC101) controls the display LCD and LEDs.
When power is on, the CPU will use the MBL line to control
the LCD illumination and key backlight LEDs.
The dimmer function is controlled by the switch Q11. The
LCD controller (IC2) controls the functions of the LCD
through the CE, CK, DI lines from the CPU.
28
CIRCUIT DESCRIPTION /
IC101
CPU
Fig. 10 Control circuit /
IC101
CPU
Fig. 11 Memory circuit /
CE
CK
IC101
DI
CPU
MBL
controller
Q6
SW
Fig. 12 Display circuit /
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