beautypg.com

Motorola M68HC08 User Manual

Page 140

background image

User Guide

Designer Reference Manual

DRM028 — Rev 0

140

User Guide

MOTOROLA

#define CURR_PIREG_I_GAINSCALELEFT 0

Range: <0,8>

/* MUST_CHANGE_5_EXPER: */

#define CURR_PIREG_I_GAIN 64

Range: <0,255>

where the current regulator integral gain is:

KP = CUR_PIREG_I_GAIN*2

CURR_PIREG_I_GAINSCALELEFT

(EQ 6-5.)

These constants can be calculated according to regulators theory. The
current sampling (regulator execution) period is PER_CS_T1_US = 128
µs, at the default software setting. Normally it does not need to be
changed (if change is required see

PWM Frequency and Current

Sampling Period Setting

). Another recommended solution is an

experimental setting.

NOTE:

CURR_PIREG_P_GAINSCALELEFT, CURR_PIREG_P_GAIN,
CURR_PIREG_I_GAINSCALELEFT, CURR_PIREG_I_GAIN can be
evaluated with PC master software tuning file tuning_bldc.pmp.

We suggest using PC master software with tuning file tuning_bldc.pmp
for regulator parameters evaluation. You can use this procedure:

1. Set const_cust_x.h:

CURR_PIREG_P_GAINSCALELEFT 0
CURR_PIREG_P_GAIN 0
CURR_PIREG_I_GAINSCALELEFT 0
CURR_PIREG_I_GAIN 0

2. Temporarily change the software: in code_start.c file, label

TUNING_1 enable goto Align (it will cause infinite time for
alignment state, where the current is tuned)

3. Build and run the code (see

Software Execution

,

Build

,

Execute

from Evaluation Board

)

4. Start the PC master software tuning project

5. Select Current Parameters Tuning subproject (see

Software

Parameters Tuning with PC Master Software Project File

) in

order to be able to modify the current regulator

6. You can see the actual current (and required alignment current)

F

re

e

sc

a

le

S

e

m

ic

o

n

d

u

c

to

r,

I

Freescale Semiconductor, Inc.

For More Information On This Product,

Go to: www.freescale.com

n

c

.

..