Kirisun TM840 Service Manual

TM840 Service Manual
3.2 Baseband Section
3.2.1Baseband System
Figure 3.7 Baseband Section Diagram
The core of the baseband control is U4, which is composed of dual core, ARM+DSP. It employs 19.2MHz clock which is
generated by external crystal as system clock and 32.768kHz as system timer. U4 provides variety of interfaces, which
allows communicating and interacting with peripheral devices and systems.
Here are some main communication interfaces:
1. SPI interface: U4 provides 2 SPI interfaces, It configures the register of PLL U103 and IF processor U4000 via SPI0 bus,
and configure and control U105. via SPI1.
2. McBSP interface: This system employs McBSP1 to achieve the data exchange between U4 and IF processor U4000, then
send the received data from receiver to DSP for further processing.
3. McASP interface: This system employs McASP to achieve the digital audio data exchange between U4 codec U17.
4 UART interface: Via UART interface, the system can achieve the data exchange between GPS and U4 controller, including
positioning information data and control command data.
5 Second Development Interface
8

Kirisun TM840 Specifications

General

Brand	Kirisun
Model	TM840
Category	Radio
Language	English