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Problems Running Tutorials 5&6 on Real Hardware

PostPosted: Thu Feb 20, 2003 12:43 pm
by aek
A Salvo Lite user has alerted us to a problem when attempting to run Salvo tutorials tu5 or tu6 on real hardware at typical (i.e. 150MHz) clock speeds -- they don't work!

This is due to an error in the Timer2 initialization. In vectors.asm, Timer2 is being initialized to generate an interrupt every 200 cyles. This time period is much too short, as it forces the application to continuously service the interrupt.

If you are having these problems, please replace the end of salvo ut u1syswvectors.asm with this code snippet:

code:
		;
; Initialize Timer2 to generate INT14 every 1,500,000 cycles using prescale.
; This gives a system tick every 10ms for a 150MHz clock.
;

MOVL XAR6,#TIMER2TPR
MOV *XAR6,#39 ; Set Divide Down count to 39
MOVL XAR6,#TIMER2PRD
MOV *XAR6,#37503 ; Set Period (1/150E6) * 37503 * 40 == 10ms
MOVL XAR6,#TIMER2TCR
MOV *XAR6,#0x4020 ; Enable timer interrupt / set control register value.
LRETR

This will set a system tick rate of 100Hz, i.e. the Timer2 interrupt will occur every 10ms.

Naturally, you can adjust the prescalar and period values to suit your application. However, we recommend that you have a minimum system tick period of 2,000 instructions.

This change will be included in future releases of Salvo for TI's TMS320C2000 DSPs.

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Re: Problems Running Tutorials 5&6 on Real Hardware

PostPosted: Tue Feb 25, 2003 2:58 am
by aek
This change has been made in the version now available (3.1.2).

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