Hytera MD78X, Service Manual

Page: 27 / 519

Circuit Description
UHF1 (400
–
470 MHz)
20

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
(Option Board
VDD=3.3 V)
Remarks
1
3
5
7
9
GPIO1
GPIO2
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 MAX=0.22VDD
GPIO5: output signal
of resetting the
option board.
GPIO4/GPIO5:
Unidirectional output
interfaces.
They
require their input
resistances
are
greater than or equal
to 47 kΩ.
11
13
15
17
UART-TX
UART-RX
UART-CTS
UART-RTS
UART
O
I
I
O
UART
2
4
I2C –SDA
I2C -SCL
I2C
I/O
O
I2C
6
8
10
12
MCBSP-DR
MCBSP-WCLK
MCBSP-DX
MCBSP-FSX
MCBSP
I
I/O
O
I/O
McBSP:
Multi-channel
buffered serial port
14 AGND AGND / / /
16 AF OB TO MB AF I
80 mV (standard
output from the option
board to the main
board)
MAX: 700mV