Texas Instruments MSP50C614 - Manual (Page 159)

Special Filter Instructions
4-67 Assembly Language Instructions
Figure 4–6. Setup and Execution of MSP50P614/MSP50C614 Filter Instructions,
N+1 Taps
Accumulators
0–15 th bits of y
Ĕ
16–31 st bits of y
Ĕ
32–47 th bits of y
Ĕ
AC r
AC r+1
AC r+2
y[k] =
Σ
m =0..N
h[ m]x[k–m]
+
Multiplier PH MR
ОООООО
ОООООО
ОООООО
ОООООО
ОООООО
ОООООО
ОООООО
ОООООО
ОООООО
Past N samples,
x[k]
ОООООО
ОООООО
ОООООО
ОООООО
ОООООО
ОООООО
ОООООО
Coefficients, h[ k]
k = 0..N
Data memory
(FIR/COR)
Program memory (FIRK/CORK)
sample_buf
coeff_array
AC r+1 AC r+2 AC r y =
For COR/CORK
AC r AC r+1 y =
For FIR/FIRK
TAG=1 for 2 nd to last sample for
Circular buffer operation
+
Accumulators Pointer
Point to accumulator, ACr A n = ACn
Circular buffer operation only
Circular buffer length, –2N R5
sample_buf address
Rx
even
{R0,R2,R4,R6}
coeff_array address
DP coeff_array address
Rx
even
+1
{R1,R3,R5,R7}
FIR/COR only
FIRK/CORK only
† The value of y is stored in ACr and ACr+1 for FIR instruction (32 bit accumulation). COR instruction uses 48 bit accumulation
and includes accumulator AC r+2.
coeff_array
Coefficients, h[ k]
k = 0..N