Texas Instruments MSP50C614 manual COR Correlation Filter Function, 3n R+2, Xeven = R xeven + R5

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±1 h[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.

4-94