TMS 470 HET instruction set help

Hi

Thanks for posting your query, but this is the forum mainly for TMS570 microcontrollers.

TMS470 HET module and TMS570 NHET module are slightly different.

However the below explanations are applicable for both TMS470 HET and TMS570 NHET modules.

--> Conditional Address defines the address of the next instruction when the condition occurs.

     ECNT instruction can be configured to use one of the Event conditions. If one of the conditions is true then the HET state machine will execute the instruction as specified in the Conditional Address.

--> MOV32 replaces the selected ALU register and/or the data field values at the remote address location depending on the move type.

Example code:

1) ECNT instruction can be used for Event Counter. The below example illustrates the use of cond_addr in ECNT instruction.

    The goal is to count the number of rising edges received on PIN2 only when PIN0 is HIGH.

    In the below HET code instruction 1(L00) executes every time but instruction 2 (L01) is executed only when the Event condition of instruction 1 occurs.

L00 ECNT{next=L00,control = OFF,prv = on,pin = 0,reg = B,event = ACCUHIGH,cond_addr =L01,irq=OFF,data =0}

          ;If (Event count condition is true) ( When Pin 0 is High)

          ;{

          ;    register B    = Immediate Data Field + 1;

          ;    Immediate Data Field = Immediate Data Field + 1;

          ;    Jump to Conditional Address ( L01);

          ;}

          ;else

          ;    Jump to Next Program Address ( L00);

L01 ECNT{next=L00,control = OFF,prv = on,pin = 2,reg = A,event = RISE,cond_addr =L00,irq=OFF,data = 0}

         ;If (Event count condition is true) ( When Rise edge detected on Pin 2)

         ;{

         ;    register A    = Immediate Data Field + 1;

         ;    Immediate Data Field = Immediate Data Field + 1;

         ;    Jump to Conditional Address ( L00);

         ;}

         ;else

         ;    Jump to Next Program Address ( L00);

2) Below example code generates PWM waveform with synchronous Duty Cycle Update using MOV32, ECMP and CNT instructions.

L00   CNT  { next= L01, reg= A, irq= OFF, max= 4 }

       ; count: increment immediate data field (counter) of this instruction

       ; and write new value to reg_A

       ; if (counter == max)

       ;         {set Z=1; reset immediate data field and reg_A to zero}

L01   ECMP  { next= L00, cond_addr= L02, en_pin_action=ON, pin = 0, action= PULSEHI, reg= A, irq= OFF,  data= 2, hr_data= 50h }

       ; if (reg_A == data_field) { set   Pin 0; go to L02 }

       ; if (      Z==1         ) { clear Pin 0             }

       ; goto L00

L02   MOV32 { next= L00, remote= L01, type= imtoreg&rem, reg= A, data= 2, hr_data=10h }

       ; update duty cycle: write immediate data field of this instruction

       ; to the compare field of ECMP (L01) and to reg_A

For more information please refer TMS570 NHET Application note from the link

http://focus.ti.com/general/docs/litabsmultiplefilelist.tsp?literatureNumber=spraba0

You can also find the windows based TMS570 NHET Simulator IDE from the link

http://focus.ti.com/docs/toolsw/folders/print/het_ide.html