nand2/07_Operating_System/03_Sys_Test/Readme.md

Sys.jack

A library that supports various program execution services.

Hint: To debug the next projects in real hardware, we can implement one or both of the following strategies into Sys.jack

1. Use LED to indicate the state of JACK-OS according to

LED[1:0]	Sys.jack	JACK-OS state
00	at entry	nothing happened yet
01	Sys.init()	start execution of Main.main()
10	Sys.halt()	Main.main() terminated succesfully
11	Sys.error(int)	a system error occured

2. We can use UART to send some chars according to the state of JACK-OS. e.g. send "GO" at Sys.init(), "HALT" at Sys.halt() and "ERR" at Sys.error(int).

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Project

• Implement Sys.jack

• Test in simulation. Change the delay time in Main.jack to 1ms.

  $ cd 03_Sys_Test
  $ make
  $ cd ../00_HACK
  $ apio clean
  $ apio sim
  

• Check, if the LED toggles every 1 milli second:

  

• run in real hardware. Set the delay to 1s = 1000ms with Sys.wait(1000) in Main.main().

  $ cd 03_Sys_Test
  $ make
  $ make upload
  

• Check if the LED change state every 1 second.