Hytera MD652, Service Manual

Page: 127 / 207

VHF1 (136
‐
174 MHz)
Circuit Description
19
UART Interface
Processor U1002 has a total of three UART interfaces, which are used to communicate with different
external devices. UART3 is used for communication with Option Board and accessory connector.
Mobile Accessory Connector (MAC)
Mobile accessory connector contains audio interface, programmable I/O port, serial port, USB port,
accessory identifier port, etc, which are available for further development. Please refer to
7.2 DB26
Accessory Interface for details.
Option Board Interface
J400, an option board interface, is used to achieve specific function by connecting to the designated
option board. The definition of each pin is listed as below:
Pin No. Signal Function
I/O of the
Radio
Voltage of
Option Board
VDD=3.3 V
Remarks
1
3
5
7
9
GPIO 2
GPIO 1
GPIO3
GPIO4
GPIO5
GPIO
GPIO
GPIO
GPIO
RESET-OUT
I/O
I/O
I/O
O
O
VIH
MIN=0.7VDD VIL
MAX=0. 3VDD
VOH
MIN=0.8VDD
VOL
GPIO5: Reset the
output signal of the
option board.
GPIO4/GPIO5:
Uni-directional
output interfaces.