Atop SE59XX-SDK, User Manual, Page: 44 / 75

SE59XX-SDK
Software development Kit
User Manual
V1.2
4
Software Specifications
The device node is the communication interface between user space and hardware device in Linux.
Each chapter is divided into two parts:
1.
How to program these interfaces
– The main pur pose is to p rovide the way to access device node
with some sample code .
2.
How to test the interface
– The main pur pose is to descr ibe the way to use Linux internal or Atop
su p por ting tools to tes t the inte r faces .
4.1 COM Port Interface
SE59XX Series (Exce p t SE5900A) are equi p p ed with COM por ts . Each COM por t is regis te red as a TTY
t e rminal inte r face with the kernel .

Maximum baud rate : 921600

Minimum baud rate : 300

Se rial inte r face sup por ted : RS232 / RS485 / RS422
The sample p rogram is in the software/atop_a p plication/utils/atop_loopback folder :
Table 4 . 1 Sample programs for COM port interface
File Name Description
r s232_loopback.c Loopback test program for RS232 ports
rs422_loopback.c Loopback test program for RS422 ports
rs485_loopback.c Loopback test program for RS485 ports
4.1.1 Program COM port interface
The following tables list the device node of COM port for each EVM model.
Table 4 . 2 SE59XX device node
Device node Major & Minor
number Device Type Description
ttyATOP0 266 0 Character ATOP COM port 1
ttyATOP1 266 1 Character ATOP COM port 2
ttyATOP2 266 2 Character ATOP COM port 3
ttyATOP3 266 3 Character ATOP COM port 4
… … … …