Kenwood TKR-740 Service Manual page 37

5.Control Circuit
The control unit (X53-388) consists of the follow ing circuits:
(1) main CPU, (2) sub CPU, (3) DSP circuit, (4) AF PA circuit,
(5) display circuit, (6) baseband circuit, (7) M icrophone AGC
circuit, (8) RS-232C circuit, and (9) pow er supply circuit.
CIRCUIT DESCRIPTION
5.1 M ain CPU
containing a 128k ROM and a 5k RAM . This CPU controls the
sub CPU, the flash ROM , and the DSP, encodes high-speed
and low -speed data, controls the transmitter unit, the receiver
unit, the control unit, and the display circuit and sends data to
or from an external device.
Fig.21 M ain CPU
The main CPU (IC17) is a 16-bit single-chip microcomputer
TKR-740
37