Kenwood TK-3401D Service Manual page 11

2.3.8.2 For Digital Voice Mode
If the digital data matches in the MCU, the digital voice payload data will go into the Vocoder in the MCU for conversion to PCM. The
PCM data will go to the baseband IC through the SPI input, where it will be converted to analog by the DAC. Analog voice will be
filtered and finally sent to the audio amplifier.
IC400
FM IC
2.3.9 dPMR Transmitting
2.3.9.1 For Digital Voice Mode
The analog voice from the microphone will go to the ADC (after the audio filter) to convert to PCM data. The PCM data will be sent to
the Vocoder through the SPI output. The Vocoder will convert the PCM to dPMR protocol, where it will be sent to the baseband through
the C-BUS. In the baseband IC, the data will be encoded and finally transmitted through the TCXO and VCO modulation.
TCXO
VCO
2.4 SEMICONDUCTOR DATA
2.4.1 MCU: 2F405VGT6KFAA (TX-RX unit IC710)
Pin Name I/O
No.
1 MINVOL O
2 DCSW O
3 APCSW O
4 TEST_1 O
5 TEST_2 O
6 VBAT -
7 BLULED O
8 BSHIFT O
9 INSPMT O
10 VSS1 -
11 VDD1 -
12 XIN I
13 NC O
14 NRST I
15 LSDI I
16 HSDDEC I
17 VOX I
18 OPT4 I/O Option port 4
19 VDD -
IC705 Baseband IC
13 16
dPMR
decoder
Audio
Output
To Audio AMP
Fig.9 dPMR receiver system
IC705 Baseband IC
23
dPMR
encoder
2 4
Audio
Filter
From MIC
Fig.10 dPMR transmit system
Function
Minimum volume control
APC voltage discharge switch
APC switch
Test land 1
Test land 2
3.3V
Blue LED light control (Hi: LED ON)
MPU clock frequency shift
Internal speaker mute
GND
3.3V
Crystal (19.2MHz)
No connection
MCU reset input
QT/DQT decode
2-tone decode
VOX level input
33MD
43 54
C-BUS C-BUS
3 79
Vocoder
SPI
42
53
C-BUS C-BUS
1 80
Vocoder
SPI
Pin Name
No.
20 VSSA
21 VREF+
22 VDDA
23 5CC
24 CVIN
25 EMPTT
26 50VC
27 VSS2
28 VDD3
29 LSDO
30 HSDENC
31 5RC
32 5TC
33 BATT
34 RSSI
35 BUSY
36 TH_DET
37 33MSC
38 OPT1
IC710 MCU
IC710 MCU
I/O Function
- GND
- 33M
- 33M
O 5C control
I VCO lock voltage (for automatic
alignment)
O Emergency PTT
O 5V AVR control for GPS MIC
option/OPT detection
- GND
- 33MD
O QT/DQT output
O BEEP/HSD output
O 5R control
O 5T control
I Battery level input
I RSSI input
I BUSY input
I Thermistor detection (Temperature
detection)
I/O 33M switch control
O Option port 1
(No.RA012<Rev.001>)1-11