diff --git a/asm/creole.py b/asm/creole.py
index bdf8ea7..0ba4cf0 100644
--- a/asm/creole.py
+++ b/asm/creole.py
@@ -214,8 +214,8 @@ class Instruction(Enum):
 	READ_DAC = 13, "_render_default", ArgType.VAL, ArgType.REG
 	WRITE_DAC = 14, "_render_default", ArgType.VAL, ArgType.VAL
 	SLEEP = 15, "_render_default", ArgType.VAL
-	CLOOP_READ = 16, "_render_default", ArgType.VAL, ArgType.REG
-	CLOOP_WRITE = 17, "_render_default", ArgType.VAL, ArgType.VAL
+	CLOOP_READ = 16, "_render_default", ArgType.VAL, ArgType.REG, ArgType.REG
+	CLOOP_WRITE = 17, "_render_default", ArgType.VAL, ArgType.VAL, ArgType.VAL
 	WF_LOAD = 18, "_render_default", ArgType.VAL, ArgType.DAT
 	WF_EXEC = 19, "_render_default", ArgType.VAL, ArgType.VAL
 	SENDVAL = 20, "_render_default", ArgType.VAL
diff --git a/creole.c b/creole.c
index 37c444b..aa80c42 100644
--- a/creole.c
+++ b/creole.c
@@ -654,13 +654,19 @@ enum creole_run_ret creole_step(struct creole_env *env, creole_word *sc)
 		break;
 	case CREOLE_CLOOP_READ:
 		check(read_val(env, &ins, 0, &a0));
-		a1 = upsilon_control_loop_read(a0);
-		check(creole_reg_write(env, ins.w[1], a1));
+		check(read_val(env, &ins, 0, &a1));
+		check(read_val(env, &ins, 0, &a2));
+		if (valid_reglen(env, a1) && valid_reglen(env, a2)) {
+			upsilon_control_loop_read(env->reg + a1,
+			                          env->reg + a2,
+			                          a0);
+		}
 		break;
 	case CREOLE_CLOOP_WRITE:
 		check(read_val(env, &ins, 0, &a0));
-		check(read_val(env, &ins, 1, &a1));
-		upsilon_control_loop_write(a0, a1);
+		check(read_val(env, &ins, 0, &a1));
+		check(read_val(env, &ins, 0, &a2));
+		upsilon_control_loop_write(a0, a1, a2);
 		break;
 	case CREOLE_WF_LOAD:
 		check(read_val(env, &ins, 0, &a0));
diff --git a/upsilon_creole.h b/upsilon_creole.h
index cf32c47..eff20a3 100644
--- a/upsilon_creole.h
+++ b/upsilon_creole.h
@@ -17,8 +17,12 @@ creole_word upsilon_get_adc(creole_word adc);
 creole_word upsilon_get_dac(creole_word adc);
 creole_word upsilon_write_dac(creole_word dac, creole_word val);
 creole_word upsilon_sleep(creole_word usec);
-creole_word upsilon_control_loop_read(creole_word reg);
-creole_word upsilon_control_loop_write(creole_word reg, creole_word val);
+creole_word upsilon_control_loop_read(creole_word *high_reg,
+                                      creole_word *low_reg,
+                                      creole_word code);
+creole_word upsilon_control_loop_write(creole_word high_val,
+                                       creole_word low_val,
+                                       creole_word code);
 creole_word upsilon_load_waveform(struct creole_env *env, creole_word slot,
                                   creole_word db);
 creole_word upsilon_exec_waveform(creole_word slot, creole_word dac);