\r
#include "FFT.h"\r
\r
+int stage = 1;\r
/**\r
* Executes a single butterfly on ALU 0-3. The inputs are the words taken from\r
* in, which will be read on various inputs of ALU 0-3. Outputs will be\r
add_offset(m.output_b_re, 2);\r
add_offset(m.output_b_im, 2);\r
\r
- if (second_half) {\r
+ if (!second_half) {\r
write_mem(m.output_a_re, res.a_re);\r
write_mem(m.output_a_im, res.a_im);\r
write_mem(m.output_b_re, res.b_re);\r
add_offset(m.input_a_im, 1);\r
add_offset(m.input_b_re, 1);\r
add_offset(m.input_b_im, 1);\r
- /* TODO: Update twiddle offsets */\r
+ \r
+ /* TODO: Is this true? */\r
+ add_offset(m.twiddle_re, (PARAM_N_t>>stage));\r
+ add_offset(m.twiddle_im, (PARAM_N_t>>stage));\r
+ use_mask(m.twiddle_re, (PARAM_N_t/2)-1);\r
+ use_mask(m.twiddle_im, (PARAM_N_t/2)-1);\r
+\r
return in;\r
}\r
\r
\r
/* Now, do half a single stage. That means N_t / 4 cycles. Since we do 2\r
* cycles on every iteration, plus one before and after the loop,\r
- * we will loop N_t / 8 - 1 times. */\r
- init_loop(LC2, (PARAM_N_t / 8) - 1);\r
+ * we will loop N_t / 8 - 1 times. We add an extra - 1 because this is a do while loop... */\r
+ init_loop(LC2, (PARAM_N_t / 8) - 1 - 1);\r
do {\r
/* Write outputs of previous cycle */\r
write_output_regular(m, out, second_half);\r
struct mems m;\r
\r
/* We need to do n_t regular stages. Since we do two stages each\r
- * iteration, we'll do n_t / 2 iterations. */\r
- init_loop(LC1, (PARAM_n_t / 2));\r
+ * iteration, we'll do n_t / 2 iterations (and a -1 because we check after looping) */\r
+ init_loop(LC1, (PARAM_n_t / 2) - 1);\r
do {\r
m = init_mem_mapping(EVEN_STAGE);\r
init_input_addresses_regular(m, EVEN_STAGE);\r
next_cycle();\r
do_half_regular_stage(m, EVEN_STAGE, FIRST_HALF);\r
do_half_regular_stage(m, EVEN_STAGE, SECOND_HALF);\r
+ stage++;\r
next_cycle();\r
init_input_addresses_regular(m, ODD_STAGE);\r
m = init_mem_mapping(ODD_STAGE);\r
next_cycle();\r
do_half_regular_stage(m, ODD_STAGE, FIRST_HALF);\r
do_half_regular_stage(m, ODD_STAGE, SECOND_HALF);\r
+ stage++;\r
} while (loop_next(LC1));\r
}\r