Altera Stratix - Page 308

7–22 Altera Corporation
Stratix Device Handbook, Volume 2 September 2004
Finite Impulse Response (FIR) Filters
clock, the users needs to load coefficients of the polyphase filter h
1
(n) and
so on. Table 7–10 summarizes the coefficient loading schedule. The
output, y(n), is clocked using the 4× clock.
Table 7–10. Polyphase Interpolation (I=4) Filter Coefficient Loading
Schedule
Cycle of 4× Clock
Coefficients to Load Corresponding RAM/ROM
1, 5,... h(0), h(4), h(8), h(12) 0, 1, 2, 3
2, 6,...
h(1), h(5), h(9), h(13) 0, 1, 2, 3
3, 7,...
h(2), h(6), h(10), h(14) 0, 1, 2, 3
4, 8,...
h(3), h(7), h(11), h(15) 0, 1, 2, 3