Filter
Top Products
Individual Instruction Descriptions
4-96
4.14.14 CORK Correlation Filter Function
Syntax
[label] name dest, src Clock, clk Word, w With RPT, clk Class
CORK An, *Rx 3 1 3(n
R
+2) 9a
Execution With RPT N–2:
(mask interrupts)
RPT counter = N–2
MR = h[0] = first filter coefficient
x = sample data pointed at by Rx
even
h[1] = second filter coefficient pointed by DP
y = result stored in three consecutive accumulators (48 bit) pointed by An
{between every accumulation}
IF TAG = 1
Rx
even
= Rx
even
+ R5 {for circular buffering}
ELSE
Rx
even
++ { 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
CORK An, *Rx 1 1 1 0 1 0 0 An 1 0 0 Rx 1 1
Description When used with repeat will execute 16 × 16 multiplication between data
memory and program memory, 48-bit accumulation, and a circular buffer
operation. Each tap takes 3 instruction cycles. 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 CORK execution, interrupt is queued.
See Also RPT, COR, FIR, FIRK
Example 4.14.13.1 RPT 0
CORK 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.