Texas Instruments MSP50C6xx - Manual (Page 154)

Special Filter Instructions
4-68
Figure 4–7. Filter Instruction and Circular Buffering for N+1 Tap Filter
16 Bits TAG
AC n+1 AC n+2 AC n y
if TAG = 1 Rx
even coeff_array
DP coeff_array
Rx
even
+1
CORK/FIRK only
COR/FIR only
h[0]
h[1]
h[2]
0
0
0
h[3]
h[4]
0
0
0
h[N–1]
0
0
0
h[N] 0
0
16 Bits 17 th Bit
coeff_array
coeff_array is stored in
program or data memory
based on filter instruction.
x[k]
x[k–1]
x[k–2]
0
0
0
x[k–3]
x[k–4]
0
0
0
x[k–N]
0
0
1
x[k+1] 0
16 Bits 17 th Bit
sample_buf
x
x
x
x
x
x
x
+
STAT
x[k–N–1] is replaced
by x[k+1]
y =
Σ
k =0..N
h[m]
×
x[k–m]
+ R5 = –2(N+1)
program memory (FIRK/CORK)
data memory (FIR/COR)
48-bit accumulation for COR/CORK
32-bit accumulation
for FIR/FIRK
17th Bit
Rx
even