Cpu Pins - HYT TC-320 Service Manual

2.2.3 Audio Power Amplifier
The audio signal output from U601 is amplified by the audio power amplifier (U301) to drive the speaker directly.
2.3 Power Supply Processing
Block diagram of power supply circuit is shown as below:
Power Supply Section: The 3.7V battery voltage is converted to two flows of 3.0V DC voltage by U602. One flow supplies
3.0V VCC for the CPU; the other outputs 3.0V V-SAVE, which goes through Q601, Q602 and Q604 respectively to supply,
under the control TX-CTRL, VT for Tx circuit and VR for Rx circuit. U602 also supplies the PLL circuit with voltage
V-SAVE.

CPU Pins

Pin No. Port
1 None
2 None
3 None
4 None
5 None
6 TXD
7 RXD
8 P60
9 P61
10 P62
11 P63
12 P64
13 P65
14 P66
15 P67
16 Vssd
U602
DC-DC
G601
BATTERY
Pin Name I/O
/
/
/
/
/
TXD O
RXD
APA_EN O
SAVE_CTL O
EXT MIC
EXT PTT
Red LED O
Green LED O
Reserve O
Reserve O
GND S
VCC
Q604
V_SAVE
/
/
/
/
/
I
Control speaker; H: unmute, L: mute
Control Power Save; in non-Power-Save status, it is at high
I Check MIC connection (valid for high level)
I PTT key on the earpiece (valid for high level)
Ground power supply for digital circuit
13
TC-320 Service Manual
SW
VR
Q602
VT
SW
Q601
Function
/
/
/
/
/
UART TxD
UART RxD
level.
Red LED
Greed LED
Reserved
Reserved