Individual Instruction Descriptions

4.14.13 COR

 

Correlation Filter Function

 

 

 

 

Syntax

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

[label]

name

 

dest, src

Clock, clk

Word, w

 

With RPT, clk

Class

 

 

 

 

 

 

 

 

 

 

 

 

COR

 

An, *Rx

3

1

 

3(nR+2)

9a

Execution

With RPT N–2:

 

 

 

 

 

 

 

 

(mask interrupts)

 

 

 

 

 

 

 

 

RPT counter = N–2

 

 

 

 

 

 

 

 

MR = h[0] = first filter coefficient

 

 

 

 

 

 

 

x = sample data pointed by Rxeven

 

 

 

 

 

 

 

h[1] = second filter coefficient pointed by Rxeven+1

 

 

 

 

 

y = result stored in three consecutive accumulators (48 bit) pointed by An

 

 

 

{between every accumulation}

 

 

 

 

 

 

 

 

IF TAG = 1

 

 

 

 

 

 

 

 

 

Rxeven = Rxeven + R5

{for circular buffering}

 

 

 

 

 

ELSE

 

 

 

 

 

 

 

 

 

Rxeven

{ if Rx++ is specified in the instruction}

 

 

 

ENDIF

 

 

 

 

 

 

 

 

PC PC + 1

 

 

 

 

 

{final result}

y+￿k+0..N–1h[k] · x[N–1–k]

(Execution is detailed in section 4.11)

Flags Affected

none

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Opcode

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Instructions

 

16

15

 

14

13

 

12

11

10

9

 

8

7

6

5

4

3

2

1

0

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

COR An, *Rx

 

1

1

 

1

0

 

1

0

0

 

An

1

1

0

 

Rx

 

1

1

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Description

When used with repeat will execute 16

16 multiplication between two

 

indirectly addressed data memory buffers, 48-bit accumulation, and a circular

 

buffer operation. Each tap takes 3 instruction cycles. The selected register Rx

 

must be even. This instruction also uses R(x+1). This instruction must be used

 

with RPT instruction. See section 4.11 for more detail on the setup of

 

coefficents and sample data. During COR execution, interrupts are queued.

See Also

RPT, CORK, FIR, FIRK

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Example 4.14.13.1

RPT 0

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

COR A0, *R0

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Computes the calculation for 2 tap correlation filter with 48 bit accumulation. See section 4.11 for more detail on the setup of coefficents and sample data.

Assembly Language Instructions

4-95

Page 181
Image 181
Texas Instruments MSP50C6xx COR Correlation Filter Function, With RPT instruction. See .11 for more detail on the setup