ZBasic Forum

Posted: **01 January 2014, 15:07 PM**

When the compiler doesn't know the value of the port in DefineCom, it assumes it is always a Software UART which is incorrect. This is only true for DefineCom3. The following code

Code: Select all

'Private inputQueue&#40;1 to 100&#41; as Byte

Public Sub Main&#40;&#41;
	Call OpenPWM8&#40;1, 50.0, zxFastPWM&#41;
	Call OpenSerialPort&#40;2&#41;
	'Call OpenQueue&#40;inputQueue, Sizeof&#40;inputQueue&#41;&#41;
	'Call OpenCom&#40;port, 9600, 0, inputQueue&#41;
End Sub	

Public Sub OpenSerialPort&#40;ByVal port as Byte&#41;
	Call DefineCom&#40;port, 0, 0, &H08&#41; ' always assumes a software UART which is incorrect
End Sub

results in the error message an application cannot use both the software UART and 8-bit PWM on the ZX24su

Posted: **01 January 2014, 18:14 PM**

mikep wrote:When the compiler doesn't know the value of the port in DefineCom, it assumes it is always a Software UART which is incorrect.

The issue is that if it doesn't make that assumption the application might be built incompletely.

If your app doesn't use any SW UART channels, you can inform the compiler thus by using:

Code: Select all

Option ComChannels 0

With that option present all vestiges of the SW UART infrastructure are eliminated from the app.

Posted: **01 January 2014, 20:35 PM**

dkinzer wrote:If your app doesn't use any SW UART channels, you can inform the compiler thus by using:
Code: Select all
Option ComChannels 0

While I understand the intent of protecting the programmer from self-induced errors, I would also say that the solution is non-obvious. Either some text should be added to the chapter on native mode or perhaps a list of all compiler warning and errors should be given with an explanation of how to avoid each one, as appropriate.

ZBasic Forum

Compiler problem always assuming Software UART

Compiler problem always assuming Software UART

Re: Compiler problem always assuming Software UART

Re: Compiler problem always assuming Software UART