HCS12 datasheet(350/452 Pages) FREESCALE

350 / 452 page

S12CPUV2 Reference Manual, Rev. 4.0

350

Freescale Semiconductor

Figure 9-5. MEM Instruction Flow Diagram

In 4b, slope_1 is zero if the left side of the trapezoid has infinite slope

(vertical). If so, the result (grade) should be $FF at and to the right of point_1

everywhere within the trapezoid as far as the left side is concerned. The

grade_1 greater than $FF term corresponds to the input being to the right of

where the left sloping side passes the $FF cutoff level. If either of these

conditions is true, the result (grade) is left at the value it got from 4a. The

“else” condition in 4b corresponds to the input falling on the sloping portion

of the left side of the trapezoid (or possibly outside the trapezoid), so the

result is grade equal grade_1. If the input was outside the trapezoid,

flag_d12n would be one and grade_1 and grade_2 would have been forced

to $00 in cycle 3. The else condition of 4b would set the result to $00.

1 - R

READ WORD @ 0,X — Point_1 AND Point_2

2 - R

READ WORD @ –2,X — Slope_1 AND Slope_2

2a — Delta_1 = ACCA – Point_1

2b — Delta_2 = Point_2 – ACCA

2c — IF (Delta_1 OR Delta_2) < 0 THEN flag_d12n = 1 ELSE flag_d12n = 0

3 - f

NO BUS ACCESS

3a — IF flag_d12n = 1 THEN Grade_1 = 0 ELSE Grade_1 = Slope_1 * Delta_1

3b — IF flag_d12n = 1 THEN Grade_2 = 0 ELSE Grade_2 = Slope_2 * Delta_2

4 - O

IF MISALIGNED THEN READ PROGRAM WORD TO FILL INSTRUCTION QUEUE ELSE NO BUS ACCESS

4a — IF (((Slope_2 = 0) OR (Grade_2 > $FF)) AND (flag_d12n = 0)) THEN GRADE = $FF

ELSE GRADE = Grade_2

4b — IF (((Slope_1 = 0) OR (Grade_1 > $FF)) AND (flag_d12n = 0)) THEN GRADE = GRADE

ELSE GRADE = Grade_1

5 - w

WRITE BYTE @ –1,Y — FUZZY INPUT RESULT (GRADE)

START

END

X = X + 4

Y = Y + 1

HCS12 Datasheet(PDF) 350 Page - Freescale Semiconductor, Inc