topic Re: Initial DAC MC56F8037 in Digital Signal Controllers

Initial DAC MC56F8037

repairDV — Sat, 13 Feb 2016 11:24:15 GMT

Good day! Is the example of assembler code initial DAC in dsc MC56F8037?

Re: Initial DAC MC56F8037

xiangjun_rong — Mon, 15 Feb 2016 07:36:35 GMT

Hi, Constantin,

Unfortunately, I have not the DAC code with assembly language and based on MC56F8037, but I have the code with PE based on MC56F82748, the DAC IP is similar for MC56F8023 and MC56F82748.

Hope it can help you.

XiangJun Rong

Re: Initial DAC MC56F8037

johnlwinters — Mon, 15 Feb 2016 20:27:03 GMT

Hi, Using CW 8.3 for DSC, I generated a project using Processor Expert Stationery.

I then added the DAC, with the default, for PE, settings.

Here is both the C code and its assembly equivalent generated to initialize the DAC for the 8037 device:

setReg16(DAC0_CTRL, 0x01U);

P:00000105: E418F1C00000 move.l #0xf1c0,R0

P:00000108: 86400001 move.w #1,X:(R0)

/* DAC0_DATA: DATA=0 */

setReg16(DAC0_DATA, 0x00U);

P:0000010A: E418F1C10000 move.l #0xf1c1,R0

P:0000010D: 86400000 move.w #0,X:(R0)

/* DAC0_MAXVAL: MAXVAL=0 */

setReg16(DAC0_MAXVAL, 0x00U);

P:0000010F: E418F1C40000 move.l #0xf1c4,R0

P:00000112: 86400000 move.w #0,X:(R0)

/* DAC0_MINVAL: MINVAL=0 */

setReg16(DAC0_MINVAL, 0x00U);

P:00000114: E418F1C30000 move.l #0xf1c3,R0

P:00000117: 86400000 move.w #0,X:(R0)

/* DAC0_STEP: STEP=0 */

setReg16(DAC0_STEP, 0x00U);

P:00000119: E418F1C20000 move.l #0xf1c2,R0

P:0000011C: 86400000 move.w #0,X:(R0)

/* DAC0_CTRL: PDN=0 */

clrReg16Bits(DAC0_CTRL, 0x01U);

P:0000011E: E418F1C00000 move.l #0xf1c0,R0

P:00000121: 80400001 bfclr #1,X:(R0)

Re: Initial DAC MC56F8037

repairDV — Tue, 16 Feb 2016 04:50:56 GMT

Good day! What is not normally in this code:

void initDAC0()

{

asm (move.w #$f08f,X:PIT0_MOD);

asm (move.w #08ff,X:PIT0_CNTR);

asm (move.w #$000f,X:PIT0_CTRL);

asm (bfset #$1000,X:SIM_PCE1);

asm (move.w #$033e,X:DAC0_MAXVAL);

asm (move.w #$f03f,X:DAC0_CTRL);

asm (move.w #$000e,X:DAC0_DATA);

asm (move.w #$0f3e,X:DAC0_STEP);

asm (move.w #$003e,X:DAC0_MINVAL);

}

Re: Initial DAC MC56F8037

xiangjun_rong — Tue, 16 Feb 2016 06:53:59 GMT

Hi, Constantin,

I think your assembly code is okay to assign a constant to a peripheral register with move.w instruction.

The assembly instruction is described in DSP56F800ERM, pls download it from the website:

MC56F84xxx|Digital Signal Controllers|NXP

XiangJun Rong

Re: Initial DAC MC56F8037

repairDV — Wed, 17 Feb 2016 01:46:26 GMT

Good day!

#pragma interrupt called

void initLED()

{

//---------GpioD

asm(bfclr #$0030,X:GPIOD_PEREN); //#$0000 0000 0000 0011 0000

asm(bfset #$0030,X:GPIOD_DDIR);

asm (bfclr #$0010,X:GPIOD_DATA);

}

void initIsr ()

{

asm (bfclr #$FFFF,X:SIM_IPS1);

asm(bfset #$00c0,X:GPIOD_PEREN); //DAC0, DAC1 0000 0000 1100 0000

}

Re: Initial DAC MC56F8037

xiangjun_rong — Wed, 17 Feb 2016 03:57:24 GMT

Hi, Constantin,

I think your assembly code is correct to configure the GPIO pin and the DAC output pins. Regarding the line "#pragma interrupt called", if the api function is called in an ISR(Interrupt Service Routine), you have to add the line "#pragma interrupt called" before the api function, which will push/pop all the registers the api function uses. If you define the ISR, you have to add "#pragma interrupt on" before the ISR so that the compiler generates the code to push/pop both PC and SR. For your case, it is unnecessary to add "#pragma interrupt called" before initLED() api function.

Hope it can help you.

Xiangjun Rong