39
TK-782
Fig. 9 Control circuit /
Control Circuit
The CPU carries out the following tasks:
1) Controls the shift register (IC7, IC8, IC508) AF MUTE,
WIDE/NARROW, T/R KEY outputs.
2) Adjusts the AF signal level of the audio processor (IC504)
and turns the filter select compounder on or off.
3) Controls the DTMF decoder (IC507).
4) Controls the LCD assembly display data.
5) Controls the PLL (IC300).
6) Controls the D/A converter (IC5) and adjusts the volume,
modulation and transmission power.
IC5
D/A
converter
IC300
PLL
IC7
Shift
register
IC8
Shift
register
IC508
Shift
register
DT
RFCK
ES
EN
OE
CS
CK
DT
AC
K
SD
CP
EP
AFCLR
AFMSKE
AFDAT
AFRDT
AFTRD
AFRTM
AFSTB
IC504
Audio
processor
IC507
DTMF
DECO.
IC511
CPU
TX-RX UNIT (A/2)
LCD ASSY
CIRCUIT DESCRIPTION /
"
Memory Circuit
The transceiver has a 2M-bit (256k x 8) flash ROM (IC510)
and an 16k-bit EEPROM (IC512). The flash ROM contains
firmware programs, data and user data which is programmed
with the FPU. The EEPROM contains adjustment data. The
CPU (IC511) controls the flash ROM through an external ad-
dress bus and an external data bus. The CPU controls the
EEPROM through two serial data lines.
"
Fig. 10 Momory circuit /
SCL
SDA
IC511
CPU
ADDRESS BUS
DATA BUS
IC510
FLASH
ROM
IC512
EEPROM
Fig. 11 Display circuit /
"
"
Display Circuit
The CPU (IC511) controls the shift register (IC508) and dis-
play LEDs. When the LG line goes high when the transceiver
is busy, Q508 turns on and the green LED on D511 lights. In
transmit mode, the LR line goes high, Q509 turns on and the
red light lights. Backlighting LEDs for the key operation unit
(D512~D517) and LCD are provided.
When the KBLC line goes high, Q512 turns on, then Q513
turns on, and the key illumination LED lights. A voltage is
applied to the LEDA line to turn on the LCD backlight.
Q512
SW
Q508
SW
Q509
SW
Q513
SW
KBLC
LG
LR
IC508
Shift
register
D511
GRN
RED
D512~517
LEDA
Summary of Contents for TK-782
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