diff --git a/autotest.c b/autotest.c
index 4540561..c686274 100644
--- a/autotest.c
+++ b/autotest.c
@@ -1053,14 +1053,14 @@ static int test_logic(struct test_state* tstate, int y, int x, int type_idx,
 
 	if (tstate->dry_run) {
 		for (lut = LUT_A; lut <= LUT_D; lut++) {
-			if (!logic_cfg->a2d[lut].lut6
-			    && !logic_cfg->a2d[lut].lut5)
+			if (!logic_cfg->a2d[lut].lut6_str
+			    && !logic_cfg->a2d[lut].lut5_str)
 				continue;
 			printf("O %c6_lut '%s' %c5_lut '%s'\n",
-				'A'+lut, logic_cfg->a2d[lut].lut6
-					? logic_cfg->a2d[lut].lut6 : "-",
-				'A'+lut, logic_cfg->a2d[lut].lut5
-					? logic_cfg->a2d[lut].lut5 : "-");
+				'A'+lut, logic_cfg->a2d[lut].lut6_str
+					? logic_cfg->a2d[lut].lut6_str : "-",
+				'A'+lut, logic_cfg->a2d[lut].lut5_str
+					? logic_cfg->a2d[lut].lut5_str : "-");
 		}
 	}
 	rc = fdev_logic_setconf(tstate->model, y, x, type_idx, logic_cfg);
@@ -1113,17 +1113,17 @@ static int test_logic(struct test_state* tstate, int y, int x, int type_idx,
 			}
 		}
 		if ((dev->pinw_req_for_cfg[i] == LI_A6
-		     && dev->u.logic.a2d[LUT_A].lut5
-		     && *dev->u.logic.a2d[LUT_A].lut5)
+		     && dev->u.logic.a2d[LUT_A].lut5_str
+		     && *dev->u.logic.a2d[LUT_A].lut5_str)
 		    || (dev->pinw_req_for_cfg[i] == LI_B6
-		        && dev->u.logic.a2d[LUT_B].lut5
-		        && *dev->u.logic.a2d[LUT_B].lut5)
+		        && dev->u.logic.a2d[LUT_B].lut5_str
+		        && *dev->u.logic.a2d[LUT_B].lut5_str)
 		    || (dev->pinw_req_for_cfg[i] == LI_C6
-			&& dev->u.logic.a2d[LUT_C].lut5
-			&& *dev->u.logic.a2d[LUT_C].lut5)
+			&& dev->u.logic.a2d[LUT_C].lut5_str
+			&& *dev->u.logic.a2d[LUT_C].lut5_str)
 		    || (dev->pinw_req_for_cfg[i] == LI_D6
-			&& dev->u.logic.a2d[LUT_D].lut5
-			&& *dev->u.logic.a2d[LUT_D].lut5)
+			&& dev->u.logic.a2d[LUT_D].lut5_str
+			&& *dev->u.logic.a2d[LUT_D].lut5_str)
 		    || (latch_logic
 			&& (dev->pinw_req_for_cfg[i] == LI_CLK
 			    || dev->pinw_req_for_cfg[i] == LI_CE))) {
@@ -1245,7 +1245,7 @@ static int test_lut_encoding(struct test_state* tstate)
 		for (type_i = 0; type_i < sizeof(idx_enum)/sizeof(*idx_enum); type_i++) {
 			for (lut = LUT_A; lut <= LUT_D; lut++) {
 				memset(&logic_cfg, 0, sizeof(logic_cfg));
-				logic_cfg.a2d[lut].lut6 = lut6_str;
+				logic_cfg.a2d[lut].lut6_str = lut6_str;
 				logic_cfg.a2d[lut].out_used = 1;
 
 				// lut6 only
@@ -1280,7 +1280,7 @@ static int test_lut_encoding(struct test_state* tstate)
 				}
 
 				// lut6 and lut5 pairs
-				logic_cfg.a2d[lut].lut5 = lut5_str;
+				logic_cfg.a2d[lut].lut5_str = lut5_str;
 				logic_cfg.a2d[lut].out_mux = MUX_O5;
 
 				sprintf(lut6_str, "(A6+~A6)*1");
@@ -1346,7 +1346,7 @@ static int test_logic_config(struct test_state* tstate)
 
 				// lut6, direct-out
 				memset(&logic_cfg, 0, sizeof(logic_cfg));
-				logic_cfg.a2d[lut].lut6 = "A1";
+				logic_cfg.a2d[lut].lut6_str = "A1";
 				logic_cfg.a2d[lut].out_used = 1;
 
 				rc = test_logic(tstate, y, x_enum[x_i],
@@ -1358,7 +1358,7 @@ static int test_logic_config(struct test_state* tstate)
 					// O6 over mux-out seems not supported
 					// on an X device.
 					memset(&logic_cfg, 0, sizeof(logic_cfg));
-					logic_cfg.a2d[lut].lut6 = "A1";
+					logic_cfg.a2d[lut].lut6_str = "A1";
 					logic_cfg.a2d[lut].out_mux = MUX_O6;
 
 					rc = test_logic(tstate, y, x_enum[x_i],
@@ -1397,7 +1397,7 @@ static int test_logic_config(struct test_state* tstate)
 
 				// lut6, ff-out
 				memset(&logic_cfg, 0, sizeof(logic_cfg));
-				logic_cfg.a2d[lut].lut6 = "A1";
+				logic_cfg.a2d[lut].lut6_str = "A1";
 				logic_cfg.a2d[lut].ff = FF_FF;
 				logic_cfg.a2d[lut].ff_mux = MUX_O6;
 				logic_cfg.a2d[lut].ff_srinit = FF_SRINIT0;
@@ -1440,7 +1440,7 @@ static int test_logic_config(struct test_state* tstate)
 
 				// lut6, latch-out
 				memset(&logic_cfg, 0, sizeof(logic_cfg));
-				logic_cfg.a2d[lut].lut6 = "A1";
+				logic_cfg.a2d[lut].lut6_str = "A1";
 				logic_cfg.a2d[lut].ff = FF_LATCH;
 				logic_cfg.a2d[lut].ff_mux = MUX_O6;
 				logic_cfg.a2d[lut].ff_srinit = FF_SRINIT0;
@@ -1464,7 +1464,7 @@ static int test_logic_config(struct test_state* tstate)
 
 				// lut6, and-latch
 				memset(&logic_cfg, 0, sizeof(logic_cfg));
-				logic_cfg.a2d[lut].lut6 = "A1";
+				logic_cfg.a2d[lut].lut6_str = "A1";
 				logic_cfg.a2d[lut].ff = FF_AND2L;
 				logic_cfg.a2d[lut].ff_mux = MUX_O6;
 				// AND2L requires SRINIT=0
@@ -1481,7 +1481,7 @@ static int test_logic_config(struct test_state* tstate)
 
 				// lut6, or-latch
 				memset(&logic_cfg, 0, sizeof(logic_cfg));
-				logic_cfg.a2d[lut].lut6 = "A1";
+				logic_cfg.a2d[lut].lut6_str = "A1";
 				logic_cfg.a2d[lut].ff = FF_OR2L;
 				logic_cfg.a2d[lut].ff_mux = MUX_O6;
 				// OR2L requires SRINIT=1
@@ -1509,7 +1509,7 @@ static int test_logic_config(struct test_state* tstate)
 				if (rc) FAIL(rc);
 
 				// . o6-direct
-				logic_cfg.a2d[lut].lut6 = "A1";
+				logic_cfg.a2d[lut].lut6_str = "A1";
 				logic_cfg.a2d[lut].out_used = 1;
 				rc = test_logic(tstate, y, x_enum[x_i],
 					idx_enum[type_i], &logic_cfg);
@@ -1531,9 +1531,9 @@ static int test_logic_config(struct test_state* tstate)
 
 				// lut6 direct-out, lut5 mux-out
 				memset(&logic_cfg, 0, sizeof(logic_cfg));
-				logic_cfg.a2d[lut].lut6 = "(A6+~A6)*A1";
+				logic_cfg.a2d[lut].lut6_str = "(A6+~A6)*A1";
 				logic_cfg.a2d[lut].out_used = 1;
-				logic_cfg.a2d[lut].lut5 = "A1*A2";
+				logic_cfg.a2d[lut].lut5_str = "A1*A2";
 				logic_cfg.a2d[lut].out_mux = MUX_O5;
 				rc = test_logic(tstate, y, x_enum[x_i],
 					idx_enum[type_i], &logic_cfg);
@@ -1607,29 +1607,29 @@ static int test_logic_config(struct test_state* tstate)
 			if (idx_enum[type_i] == DEV_LOG_X) {
 				// minimum-config X device
 				memset(&logic_cfg, 0, sizeof(logic_cfg));
-				logic_cfg.a2d[LUT_A].lut6 = "(A6+~A6)*A1";
-				logic_cfg.a2d[LUT_A].lut5 = "A2";
+				logic_cfg.a2d[LUT_A].lut6_str = "(A6+~A6)*A1";
+				logic_cfg.a2d[LUT_A].lut5_str = "A2";
 				logic_cfg.a2d[LUT_A].out_mux = MUX_5Q;
 				logic_cfg.a2d[LUT_A].ff5_srinit = FF_SRINIT0;
 				logic_cfg.a2d[LUT_A].ff = FF_FF;
 				logic_cfg.a2d[LUT_A].ff_mux = MUX_O6;
 				logic_cfg.a2d[LUT_A].ff_srinit = FF_SRINIT0;
-				logic_cfg.a2d[LUT_B].lut6 = "(A6+~A6)*A4";
-				logic_cfg.a2d[LUT_B].lut5 = "A3";
+				logic_cfg.a2d[LUT_B].lut6_str = "(A6+~A6)*A4";
+				logic_cfg.a2d[LUT_B].lut5_str = "A3";
 				logic_cfg.a2d[LUT_B].out_mux = MUX_5Q;
 				logic_cfg.a2d[LUT_B].ff5_srinit = FF_SRINIT0;
 				logic_cfg.a2d[LUT_B].ff = FF_FF;
 				logic_cfg.a2d[LUT_B].ff_mux = MUX_O6;
 				logic_cfg.a2d[LUT_B].ff_srinit = FF_SRINIT0;
-				logic_cfg.a2d[LUT_C].lut6 = "(A6+~A6)*(A2+A5)";
-				logic_cfg.a2d[LUT_C].lut5 = "A3+A4";
+				logic_cfg.a2d[LUT_C].lut6_str = "(A6+~A6)*(A2+A5)";
+				logic_cfg.a2d[LUT_C].lut5_str = "A3+A4";
 				logic_cfg.a2d[LUT_C].out_mux = MUX_5Q;
 				logic_cfg.a2d[LUT_C].ff5_srinit = FF_SRINIT0;
 				logic_cfg.a2d[LUT_C].ff = FF_FF;
 				logic_cfg.a2d[LUT_C].ff_mux = MUX_O6;
 				logic_cfg.a2d[LUT_C].ff_srinit = FF_SRINIT0;
-				logic_cfg.a2d[LUT_D].lut6 = "(A6+~A6)*A3";
-				logic_cfg.a2d[LUT_D].lut5 = "A3+A5";
+				logic_cfg.a2d[LUT_D].lut6_str = "(A6+~A6)*A3";
+				logic_cfg.a2d[LUT_D].lut5_str = "A3+A5";
 				logic_cfg.a2d[LUT_D].out_mux = MUX_5Q;
 				logic_cfg.a2d[LUT_D].ff5_srinit = FF_SRINIT0;
 				logic_cfg.a2d[LUT_D].ff = FF_FF;
@@ -1646,26 +1646,26 @@ static int test_logic_config(struct test_state* tstate)
 			}
 			// cout
 			memset(&logic_cfg, 0, sizeof(logic_cfg));
-			logic_cfg.a2d[LUT_A].lut6 = "(A6+~A6)*(~A5)";
-			logic_cfg.a2d[LUT_A].lut5 = "1";
+			logic_cfg.a2d[LUT_A].lut6_str = "(A6+~A6)*(~A5)";
+			logic_cfg.a2d[LUT_A].lut5_str = "1";
 			logic_cfg.a2d[LUT_A].cy0 = CY0_O5;
 			logic_cfg.a2d[LUT_A].ff = FF_FF;
 			logic_cfg.a2d[LUT_A].ff_mux = MUX_XOR;
 			logic_cfg.a2d[LUT_A].ff_srinit = FF_SRINIT0;
-			logic_cfg.a2d[LUT_B].lut6 = "(A6+~A6)*(A5)";
-			logic_cfg.a2d[LUT_B].lut5 = "1";
+			logic_cfg.a2d[LUT_B].lut6_str = "(A6+~A6)*(A5)";
+			logic_cfg.a2d[LUT_B].lut5_str = "1";
 			logic_cfg.a2d[LUT_B].cy0 = CY0_O5;
 			logic_cfg.a2d[LUT_B].ff = FF_FF;
 			logic_cfg.a2d[LUT_B].ff_mux = MUX_XOR;
 			logic_cfg.a2d[LUT_B].ff_srinit = FF_SRINIT0;
-			logic_cfg.a2d[LUT_C].lut6 = "(A6+~A6)*(A5)";
-			logic_cfg.a2d[LUT_C].lut5 = "1";
+			logic_cfg.a2d[LUT_C].lut6_str = "(A6+~A6)*(A5)";
+			logic_cfg.a2d[LUT_C].lut5_str = "1";
 			logic_cfg.a2d[LUT_C].cy0 = CY0_O5;
 			logic_cfg.a2d[LUT_C].ff = FF_FF;
 			logic_cfg.a2d[LUT_C].ff_mux = MUX_XOR;
 			logic_cfg.a2d[LUT_C].ff_srinit = FF_SRINIT0;
-			logic_cfg.a2d[LUT_D].lut6 = "(A6+~A6)*(A5)";
-			logic_cfg.a2d[LUT_D].lut5 = "1";
+			logic_cfg.a2d[LUT_D].lut6_str = "(A6+~A6)*(A5)";
+			logic_cfg.a2d[LUT_D].lut5_str = "1";
 			logic_cfg.a2d[LUT_D].cy0 = CY0_O5;
 			logic_cfg.a2d[LUT_D].ff = FF_FF;
 			logic_cfg.a2d[LUT_D].ff_mux = MUX_XOR;
@@ -1682,10 +1682,10 @@ static int test_logic_config(struct test_state* tstate)
 
 			// f8 out-mux
 			memset(&logic_cfg, 0, sizeof(logic_cfg));
-			logic_cfg.a2d[LUT_A].lut6 = "~A5";
-			logic_cfg.a2d[LUT_B].lut6 = "(A5)";
-			logic_cfg.a2d[LUT_C].lut6 = "A5";
-			logic_cfg.a2d[LUT_D].lut6 = "((A5))";
+			logic_cfg.a2d[LUT_A].lut6_str = "~A5";
+			logic_cfg.a2d[LUT_B].lut6_str = "(A5)";
+			logic_cfg.a2d[LUT_C].lut6_str = "A5";
+			logic_cfg.a2d[LUT_D].lut6_str = "((A5))";
 			logic_cfg.a2d[LUT_B].out_mux = MUX_F8;
 			rc = test_logic(tstate, y, x_enum[x_i],
 				idx_enum[type_i], &logic_cfg);
@@ -1704,8 +1704,8 @@ static int test_logic_config(struct test_state* tstate)
 
 			// f7amux
 			memset(&logic_cfg, 0, sizeof(logic_cfg));
-			logic_cfg.a2d[LUT_A].lut6 = "~A5";
-			logic_cfg.a2d[LUT_B].lut6 = "(A5)";
+			logic_cfg.a2d[LUT_A].lut6_str = "~A5";
+			logic_cfg.a2d[LUT_B].lut6_str = "(A5)";
 			logic_cfg.a2d[LUT_A].out_mux = MUX_F7;
 			rc = test_logic(tstate, y, x_enum[x_i],
 				idx_enum[type_i], &logic_cfg);
@@ -1724,8 +1724,8 @@ static int test_logic_config(struct test_state* tstate)
 
 			// f7bmux
 			memset(&logic_cfg, 0, sizeof(logic_cfg));
-			logic_cfg.a2d[LUT_C].lut6 = "~A5";
-			logic_cfg.a2d[LUT_D].lut6 = "(A5)";
+			logic_cfg.a2d[LUT_C].lut6_str = "~A5";
+			logic_cfg.a2d[LUT_D].lut6_str = "(A5)";
 			logic_cfg.a2d[LUT_C].out_mux = MUX_F7;
 			rc = test_logic(tstate, y, x_enum[x_i],
 				idx_enum[type_i], &logic_cfg);
diff --git a/blinking_led.c b/blinking_led.c
index e12796e..7d12f8c 100644
--- a/blinking_led.c
+++ b/blinking_led.c
@@ -100,20 +100,20 @@ int main(int argc, char** argv)
 		}
 		if (!cur_bit) { // first bit
 			logic_cfg.precyinit = PRECYINIT_0;
-			logic_cfg.a2d[LUT_A].lut6 = "(A6+~A6)*(~A5)";
-			logic_cfg.a2d[LUT_A].lut5 = "1";
+			logic_cfg.a2d[LUT_A].lut6_str = "(A6+~A6)*(~A5)";
+			logic_cfg.a2d[LUT_A].lut5_str = "1";
 			logic_cfg.a2d[LUT_A].cy0 = CY0_O5;
 			logic_cfg.a2d[LUT_A].ff = FF_FF;
 			logic_cfg.a2d[LUT_A].ff_mux = MUX_XOR;
 			logic_cfg.a2d[LUT_A].ff_srinit = FF_SRINIT0;
 		} else if (cur_bit == param_highest_bit) {
-			logic_cfg.a2d[cur_bit%4].lut6 = "A5";
+			logic_cfg.a2d[cur_bit%4].lut6_str = "A5";
 			logic_cfg.a2d[cur_bit%4].ff = FF_FF;
 			logic_cfg.a2d[cur_bit%4].ff_mux = MUX_XOR;
 			logic_cfg.a2d[cur_bit%4].ff_srinit = FF_SRINIT0;
 		} else {
-			logic_cfg.a2d[cur_bit%4].lut6 = "(A6+~A6)*(A5)";
-			logic_cfg.a2d[cur_bit%4].lut5 = "0";
+			logic_cfg.a2d[cur_bit%4].lut6_str = "(A6+~A6)*(A5)";
+			logic_cfg.a2d[cur_bit%4].lut5_str = "0";
 			logic_cfg.a2d[cur_bit%4].cy0 = CY0_O5;
 			logic_cfg.a2d[cur_bit%4].ff = FF_FF;
 			logic_cfg.a2d[cur_bit%4].ff_mux = MUX_XOR;
@@ -139,18 +139,18 @@ int main(int argc, char** argv)
 			fnet_add_port(&model, clock_net, cur_y, logic_x, DEV_LOGIC, logic_type_idx, LI_CLK);
 
 			// lut5 net (drive vcc into A6 to enable lut5)
-			if (logic_cfg.a2d[LUT_A].lut5
-			    || logic_cfg.a2d[LUT_B].lut5
-			    || logic_cfg.a2d[LUT_C].lut5
-			    || logic_cfg.a2d[LUT_D].lut5) {
+			if (logic_cfg.a2d[LUT_A].lut5_str
+			    || logic_cfg.a2d[LUT_B].lut5_str
+			    || logic_cfg.a2d[LUT_C].lut5_str
+			    || logic_cfg.a2d[LUT_D].lut5_str) {
 				fnet_new(&model, &net);
-				if (logic_cfg.a2d[LUT_A].lut5)
+				if (logic_cfg.a2d[LUT_A].lut5_str)
 					fnet_add_port(&model, net, cur_y, logic_x, DEV_LOGIC, logic_type_idx, LI_A6);
-				if (logic_cfg.a2d[LUT_B].lut5)
+				if (logic_cfg.a2d[LUT_B].lut5_str)
 					fnet_add_port(&model, net, cur_y, logic_x, DEV_LOGIC, logic_type_idx, LI_B6);
-				if (logic_cfg.a2d[LUT_C].lut5)
+				if (logic_cfg.a2d[LUT_C].lut5_str)
 					fnet_add_port(&model, net, cur_y, logic_x, DEV_LOGIC, logic_type_idx, LI_C6);
-				if (logic_cfg.a2d[LUT_D].lut5)
+				if (logic_cfg.a2d[LUT_D].lut5_str)
 					fnet_add_port(&model, net, cur_y, logic_x, DEV_LOGIC, logic_type_idx, LI_D6);
 				fnet_vcc_gnd(&model, net, /*is_vcc*/ 1);
 			}
diff --git a/libs/bit_frames.c b/libs/bit_frames.c
index 4406f1e..e1c5106 100644
--- a/libs/bit_frames.c
+++ b/libs/bit_frames.c
@@ -1220,8 +1220,8 @@ static int extract_logic(struct extract_state* es)
 				rc = lut2str(lut_ML[LUT_A], l_col
 					  ? XC6_LMAP_XL_L_A : XC6_LMAP_XM_M_A,
 					lut5_used,
-					lut6_ml[LUT_A], &cfg_ml.a2d[LUT_A].lut6,
-					lut5_ml[LUT_A], &cfg_ml.a2d[LUT_A].lut5);
+					lut6_ml[LUT_A], &cfg_ml.a2d[LUT_A].lut6_str,
+					lut5_ml[LUT_A], &cfg_ml.a2d[LUT_A].lut5_str);
 				if (rc) FAIL(rc);
 			}
 			// ML-B
@@ -1245,8 +1245,8 @@ static int extract_logic(struct extract_state* es)
 				rc = lut2str(lut_ML[LUT_B], l_col
 					  ? XC6_LMAP_XL_L_B : XC6_LMAP_XM_M_B,
 					lut5_used,
-					lut6_ml[LUT_B], &cfg_ml.a2d[LUT_B].lut6,
-					lut5_ml[LUT_B], &cfg_ml.a2d[LUT_B].lut5);
+					lut6_ml[LUT_B], &cfg_ml.a2d[LUT_B].lut6_str,
+					lut5_ml[LUT_B], &cfg_ml.a2d[LUT_B].lut5_str);
 				if (rc) FAIL(rc);
 			}
 			// ML-C
@@ -1270,8 +1270,8 @@ static int extract_logic(struct extract_state* es)
 				rc = lut2str(lut_ML[LUT_C], l_col
 					  ? XC6_LMAP_XL_L_C : XC6_LMAP_XM_M_C,
 					lut5_used,
-					lut6_ml[LUT_C], &cfg_ml.a2d[LUT_C].lut6,
-					lut5_ml[LUT_C], &cfg_ml.a2d[LUT_C].lut5);
+					lut6_ml[LUT_C], &cfg_ml.a2d[LUT_C].lut6_str,
+					lut5_ml[LUT_C], &cfg_ml.a2d[LUT_C].lut5_str);
 				if (rc) FAIL(rc);
 			}
 			// ML-D
@@ -1295,8 +1295,8 @@ static int extract_logic(struct extract_state* es)
 				rc = lut2str(lut_ML[LUT_D], l_col
 					  ? XC6_LMAP_XL_L_D : XC6_LMAP_XM_M_D,
 					lut5_used,
-					lut6_ml[LUT_D], &cfg_ml.a2d[LUT_D].lut6,
-					lut5_ml[LUT_D], &cfg_ml.a2d[LUT_D].lut5);
+					lut6_ml[LUT_D], &cfg_ml.a2d[LUT_D].lut6_str,
+					lut5_ml[LUT_D], &cfg_ml.a2d[LUT_D].lut5_str);
 				if (rc) FAIL(rc);
 			}
 			// X-A
@@ -1309,8 +1309,8 @@ static int extract_logic(struct extract_state* es)
 				rc = lut2str(lut_X[LUT_A], l_col
 					  ? XC6_LMAP_XL_X_A : XC6_LMAP_XM_X_A,
 					lut5_used,
-					lut6_x[LUT_A], &cfg_x.a2d[LUT_A].lut6,
-					lut5_x[LUT_A], &cfg_x.a2d[LUT_A].lut5);
+					lut6_x[LUT_A], &cfg_x.a2d[LUT_A].lut6_str,
+					lut5_x[LUT_A], &cfg_x.a2d[LUT_A].lut5_str);
 				if (rc) FAIL(rc);
 			
 			}
@@ -1324,8 +1324,8 @@ static int extract_logic(struct extract_state* es)
 				rc = lut2str(lut_X[LUT_B], l_col
 					  ? XC6_LMAP_XL_X_B : XC6_LMAP_XM_X_B,
 					lut5_used,
-					lut6_x[LUT_B], &cfg_x.a2d[LUT_B].lut6,
-					lut5_x[LUT_B], &cfg_x.a2d[LUT_B].lut5);
+					lut6_x[LUT_B], &cfg_x.a2d[LUT_B].lut6_str,
+					lut5_x[LUT_B], &cfg_x.a2d[LUT_B].lut5_str);
 				if (rc) FAIL(rc);
 			
 			}
@@ -1339,8 +1339,8 @@ static int extract_logic(struct extract_state* es)
 				rc = lut2str(lut_X[LUT_C], l_col
 					  ? XC6_LMAP_XL_X_C : XC6_LMAP_XM_X_C,
 					lut5_used,
-					lut6_x[LUT_C], &cfg_x.a2d[LUT_C].lut6,
-					lut5_x[LUT_C], &cfg_x.a2d[LUT_C].lut5);
+					lut6_x[LUT_C], &cfg_x.a2d[LUT_C].lut6_str,
+					lut5_x[LUT_C], &cfg_x.a2d[LUT_C].lut5_str);
 				if (rc) FAIL(rc);
 			
 			}
@@ -1354,8 +1354,8 @@ static int extract_logic(struct extract_state* es)
 				rc = lut2str(lut_X[LUT_D], l_col
 					  ? XC6_LMAP_XL_X_D : XC6_LMAP_XM_X_D,
 					lut5_used,
-					lut6_x[LUT_D], &cfg_x.a2d[LUT_D].lut6,
-					lut5_x[LUT_D], &cfg_x.a2d[LUT_D].lut5);
+					lut6_x[LUT_D], &cfg_x.a2d[LUT_D].lut6_str,
+					lut5_x[LUT_D], &cfg_x.a2d[LUT_D].lut5_str);
 				if (rc) FAIL(rc);
 			
 			}
@@ -2765,24 +2765,24 @@ static int str2lut(uint64_t *lut, int lut_pos, const struct fpgadev_logic_a2d *a
 	int lut6_used, lut5_used, lut_map[64], rc;
 	uint64_t u64;
 
-	lut6_used = a2d->lut6 && a2d->lut6[0];
-	lut5_used = a2d->lut5 && a2d->lut5[0];
+	lut6_used = a2d->lut6_str && a2d->lut6_str[0];
+	lut5_used = a2d->lut5_str && a2d->lut5_str[0];
 	if (!lut6_used && !lut5_used)
 		return 0;
 
 	if (lut5_used) {
 		if (!lut6_used) u64 = 0;
 		else {
-			rc = bool_str2bits(a2d->lut6, &u64, 32);
+			rc = bool_str2bits(a2d->lut6_str, &u64, 32);
 			if (rc) FAIL(rc);
 			u64 <<= 32;
 		}
-		rc = bool_str2bits(a2d->lut5, &u64, 32);
+		rc = bool_str2bits(a2d->lut5_str, &u64, 32);
 		if (rc) FAIL(rc);
 		xc6_lut_bitmap(lut_pos, &lut_map, 32);
 	} else {
 		// lut6_used only
-		rc = bool_str2bits(a2d->lut6, &u64, 64);
+		rc = bool_str2bits(a2d->lut6_str, &u64, 64);
 		if (rc) FAIL(rc);
 		xc6_lut_bitmap(lut_pos, &lut_map, 64);
 	}
diff --git a/libs/control.c b/libs/control.c
index ee8352c..4bbb4be 100644
--- a/libs/control.c
+++ b/libs/control.c
@@ -419,14 +419,14 @@ int fdev_logic_setconf(struct fpga_model* model, int y, int x,
 	for (lut = LUT_A; lut <= LUT_D; lut++) {
 		if (logic_cfg->a2d[lut].out_used)
 			dev->u.logic.a2d[lut].out_used = 1;
-		if (logic_cfg->a2d[lut].lut6) {
+		if (logic_cfg->a2d[lut].lut6_str) {
 			rc = fdev_logic_a2d_lut(model, y, x, type_idx,
-				lut, 6, logic_cfg->a2d[lut].lut6, ZTERM);
+				lut, 6, logic_cfg->a2d[lut].lut6_str, ZTERM);
 			if (rc) FAIL(rc);
 		}
-		if (logic_cfg->a2d[lut].lut5) {
+		if (logic_cfg->a2d[lut].lut5_str) {
 			rc = fdev_logic_a2d_lut(model, y, x, type_idx,
-				lut, 5, logic_cfg->a2d[lut].lut5, ZTERM);
+				lut, 5, logic_cfg->a2d[lut].lut5_str, ZTERM);
 			if (rc) FAIL(rc);
 		}
 		if (logic_cfg->a2d[lut].ff) {
@@ -500,8 +500,8 @@ int fdev_logic_a2d_lut(struct fpga_model* model, int y, int x, int type_idx,
 	if (rc) FAIL(rc);
 
 	lut_ptr = (lut_5or6 == 5)
-		? &dev->u.logic.a2d[lut_a2d].lut5
-		: &dev->u.logic.a2d[lut_a2d].lut6;
+		? &dev->u.logic.a2d[lut_a2d].lut5_str
+		: &dev->u.logic.a2d[lut_a2d].lut6_str;
 	if (*lut_ptr == 0) {
 		*lut_ptr = malloc(MAX_LUT_LEN);
 		if (!(*lut_ptr)) FAIL(ENOMEM);
@@ -945,17 +945,17 @@ int fdev_set_required_pins(struct fpga_model* model, int y, int x, int type,
 				// LI_AX..LI_DX are in sequence
 				add_req_inpin(dev, LI_AX+i);
 			}
-			if (dev->u.logic.a2d[i].lut6) {
-				scan_lut_digits(dev->u.logic.a2d[i].lut6, digits);
+			if (dev->u.logic.a2d[i].lut6_str) {
+				scan_lut_digits(dev->u.logic.a2d[i].lut6_str, digits);
 				for (j = 0; j < 6; j++) {
 					if (!digits[j]) continue;
 					add_req_inpin(dev, LI_A1+i*6+j);
 				}
 			}
-			if (dev->u.logic.a2d[i].lut5) {
+			if (dev->u.logic.a2d[i].lut5_str) {
 				// A6 must be high/vcc if lut5 is used
 				add_req_inpin(dev, LI_A6+i*6);
-				scan_lut_digits(dev->u.logic.a2d[i].lut5, digits);
+				scan_lut_digits(dev->u.logic.a2d[i].lut5_str, digits);
 				for (j = 0; j < 6; j++) {
 					if (!digits[j]) continue;
 					add_req_inpin(dev, LI_A1+i*6+j);
@@ -993,10 +993,10 @@ void fdev_delete(struct fpga_model* model, int y, int x, int type, int type_idx)
 	dev->pinw_req_in = 0;
 	if (dev->type == DEV_LOGIC) {
 		for (i = LUT_A; i <= LUT_D; i++) {
-			free(dev->u.logic.a2d[i].lut6);
-			dev->u.logic.a2d[i].lut6 = 0;
-			free(dev->u.logic.a2d[i].lut5);
-			dev->u.logic.a2d[i].lut5 = 0;
+			free(dev->u.logic.a2d[i].lut6_str);
+			dev->u.logic.a2d[i].lut6_str = 0;
+			free(dev->u.logic.a2d[i].lut5_str);
+			dev->u.logic.a2d[i].lut5_str = 0;
 		}
 	}
 	dev->instantiated = 0;
diff --git a/libs/floorplan.c b/libs/floorplan.c
index e2484c3..29b875b 100644
--- a/libs/floorplan.c
+++ b/libs/floorplan.c
@@ -327,12 +327,12 @@ static int printf_LOGIC(FILE* f, struct fpga_model* model,
 		}
 		cfg = &tile->devs[i].u.logic;
 		for (j = LUT_D; j >= LUT_A; j--) {
-			if (cfg->a2d[j].lut6 && cfg->a2d[j].lut6[0])
+			if (cfg->a2d[j].lut6_str && cfg->a2d[j].lut6_str[0])
 				fprintf(f, "%s %c6_lut %s\n", pref, 'A'+j,
-					cfg->a2d[j].lut6);
-			if (cfg->a2d[j].lut5 && cfg->a2d[j].lut5[0])
+					cfg->a2d[j].lut6_str);
+			if (cfg->a2d[j].lut5_str && cfg->a2d[j].lut5_str[0])
 				fprintf(f, "%s %c5_lut %s\n", pref, 'A'+j,
-					cfg->a2d[j].lut5);
+					cfg->a2d[j].lut5_str);
 			if (cfg->a2d[j].out_used)
 				fprintf(f, "%s %c_used\n", pref, 'A'+j);
 			switch (cfg->a2d[j].ff) {
diff --git a/libs/model.h b/libs/model.h
index c44afdd..8b98c5a 100644
--- a/libs/model.h
+++ b/libs/model.h
@@ -431,8 +431,8 @@ enum { PRECYINIT_0 = 1, PRECYINIT_1, PRECYINIT_AX };
 struct fpgadev_logic_a2d
 {
 	int out_used;
-	char* lut6;
-	char* lut5;
+	char* lut6_str;
+	char* lut5_str;
 	int ff_mux;	// O6, O5, X, F7(a/c), F8(b), MC31(d), CY, XOR
 	int ff_srinit;	// SRINIT0, SRINIT1 
 	int ff5_srinit; // SRINIT0, SRINIT1