Texas Instruments MSP50C614 manual Be even. During Firk execution, interrupts are queued

Individual Instruction Descriptions

4.14.19 FIRK				FIR Filter Function (Coefficients in ROM)
Syntax
	[label]	name		dest, src	Clock, clk		Word, w	With RPT, clk	Class
		FIRK		An, *Rx	2		1	2(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 DP
			y = result stored in three consecutive accumulators (32 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
FIRK An, *Rx		1	1	1	0	1	0	0	An		0	0	0		Rx		1	1
Description	Finite impluse response (FIR) filter. Execute finite impulse response filter taps
	using coefficients from program memory and samples from data memory.

Address reference for data memory is indirect using specified Rx and address reference for program memory is contained in DP register.

	This instruction must be used with RPT instruction. When used with the repeat
	counter it will execute 16 ⋅ 16 multiplication between indirect addressed data
	memory buffer and program memory (coef), 32-bit accumulation, and circular
	buffer operation. Each tap executes in 2 cycles. See section 4.11 for more
	detail on the setup of coefficents and sample data. Selected register Rx must
	be even. During FIRK execution, interrupts are queued.
See Also	RPT, FIR, COR, CORK
Example 4.14.19.1	RPT 0

FIRK A0, *R0

Computes the calculation for 2 tap FIR filter with 32 bit accumulation. See section 4.11 for more detail on the setup of coefficients and sample data.

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