diff --git a/software/ring-hello.c b/software/ring-hello.c
index 2095f7c..41a0ea6 100644
--- a/software/ring-hello.c
+++ b/software/ring-hello.c
@@ -20,8 +20,10 @@ int main(void) {
 
   setup_ucie(UCIE0_REG_BASE);
   reg_write64(UCIE0_REG_BASE + UCIE_MAINBAND_MODE, UCIE_BAND_MODE_TL);
+  reset_datapath(UCIE0_REG_BASE);
   setup_ucie(UCIE1_REG_BASE);
   reg_write64(UCIE1_REG_BASE + UCIE_MAINBAND_MODE, UCIE_BAND_MODE_TL);
+  reset_datapath(UCIE1_REG_BASE);
 
   int next = (chip_id % 4) + 1;
   int prev = ((chip_id + 2) % 4) + 1;
diff --git a/software/router.c b/software/router.c
index e4d19b4..1933b04 100644
--- a/software/router.c
+++ b/software/router.c
@@ -50,6 +50,7 @@ int main(void) {
   if (chip_id == 1) {
     setup_ucie(UCIE0_REG_BASE);
     reg_write64(UCIE0_REG_BASE + UCIE_MAINBAND_MODE, UCIE_BAND_MODE_TL);
+    reset_datapath(UCIE0_REG_BASE);
     printf("Set up UCIe 0 for chip 1\n");
     program_router(0, 2, 0); // Chip 1 UCIe0 -> Chip 2 UCIe1
     rw_mem(OFFCHIP_OFFSET * 2);
@@ -57,6 +58,7 @@ int main(void) {
   } else {
     setup_ucie(UCIE1_REG_BASE);
     reg_write64(UCIE1_REG_BASE + UCIE_MAINBAND_MODE, UCIE_BAND_MODE_TL);
+    reset_datapath(UCIE1_REG_BASE);
     printf("Set up UCIe 1 for chip 2\n");
     program_router(0, 1, 1); // Chip 2 UCIe1 -> Chip 1 UCIe0
     rw_mem(OFFCHIP_OFFSET * 1);
diff --git a/software/tacit-always.c b/software/tacit-always.c
index 0037349..3b597cf 100644
--- a/software/tacit-always.c
+++ b/software/tacit-always.c
@@ -36,7 +36,8 @@ static void branch_workload(void)
 
 int main(void)
 {
-  for (unsigned tile = 0; tile < 3; tile++) {
+  // One encoder per tile: the Shuttle tile and Rocket.
+  for (unsigned tile = 0; tile < 2; tile++) {
     tacit_select_always(tile);
   }
   branch_workload();
diff --git a/software/ucie-loopback.c b/software/ucie-loopback.c
index be5ad6f..22fd3e0 100644
--- a/software/ucie-loopback.c
+++ b/software/ucie-loopback.c
@@ -54,9 +54,11 @@ int main(void) {
   printf("Setting up UCIe0\n");
   setup_ucie(UCIE0_REG_BASE);
   reg_write64(UCIE0_REG_BASE + UCIE_MAINBAND_MODE, UCIE_BAND_MODE_TL);
+  reset_datapath(UCIE0_REG_BASE);
   printf("Setting up UCIe1\n");
   setup_ucie(UCIE1_REG_BASE);
   reg_write64(UCIE1_REG_BASE + UCIE_MAINBAND_MODE, UCIE_BAND_MODE_TL);
+  reset_datapath(UCIE1_REG_BASE);
 
   printf("Testing UCIe at port 0\n");
   program_router(0, 1, 0);
diff --git a/software/ucie-vec-memcpy.c b/software/ucie-vec-memcpy.c
index 7500c9e..afef76d 100644
--- a/software/ucie-vec-memcpy.c
+++ b/software/ucie-vec-memcpy.c
@@ -1,7 +1,7 @@
 // two-chip UCIe RVV memcpy test
 //
-// hart 0/1 are the Shuttle/OPU cores 
-// hart 2 is the Rocket tile with Saturn DMA
+// hart 0 is the Shuttle/OPU core
+// hart 1 is the Rocket tile with Saturn DMA
 // BENCH_HART_ID picks which hart runs this test
 
 #include <stdint.h>
@@ -24,10 +24,10 @@
 #define COPY_BYTES 256
 #endif
 
-// Which hart runs the test. Hart 2 is the Saturn-DMA-only rocket tile added
+// Which hart runs the test. Hart 1 is the Saturn-DMA-only rocket tile added
 // by IrisConfig's "Saturn DMA" line. Tunable: -DBENCH_HART_ID=<n>.
 #ifndef BENCH_HART_ID
-#define BENCH_HART_ID 2
+#define BENCH_HART_ID 1
 #endif
 
 // Aligned to the 32-byte beat so the natural-alignment path is exercised.
@@ -57,6 +57,7 @@ void __main(void)
     // ============================================================
     setup_ucie(UCIE0_REG_BASE);
     reg_write64(UCIE0_REG_BASE + UCIE_MAINBAND_MODE, UCIE_BAND_MODE_TL);
+    reset_datapath(UCIE0_REG_BASE);
     program_router(0, 2, 0);
 
     uint64_t peer_chip_id = 2;
@@ -90,6 +91,7 @@ void __main(void)
     // ============================================================
     setup_ucie(UCIE1_REG_BASE);
     reg_write64(UCIE1_REG_BASE + UCIE_MAINBAND_MODE, UCIE_BAND_MODE_TL);
+    reset_datapath(UCIE1_REG_BASE);
     program_router(0, 1, 1);
 
     *done_flag = 0;
diff --git a/software/ucie.h b/software/ucie.h
index a01c8fe..286df8c 100644
--- a/software/ucie.h
+++ b/software/ucie.h
@@ -16,48 +16,51 @@
 #define UCIE_TX_DATA_MODE 0x10ULL
 #define UCIE_TX_LFSR_SEED 0x18ULL
 #define UCIE_TX_LFSR_SEED_WIDTH 0x8ULL
-#define UCIE_TX_RST 0xb0ULL
-#define UCIE_TX_EXECUTE 0xb8ULL
-#define UCIE_TX_WRITE_CHUNK 0xc0ULL
-#define UCIE_TX_PACKETS_SENT 0xc8ULL
-#define UCIE_TX_MANUAL_REPEAT_PERIOD 0xd0ULL
-#define UCIE_TX_PACKETS_TO_SEND 0xd8ULL
-#define UCIE_TX_CLK_P 0xe0ULL
-#define UCIE_TX_CLK_N 0xe8ULL
-#define UCIE_TX_DATA_LANE_GROUP 0xf0ULL
-#define UCIE_TX_DATA_OFFSET 0xf8ULL
-#define UCIE_TX_DATA_CHUNK_IN0 0x100ULL
-#define UCIE_TX_DATA_CHUNK_IN1 0x108ULL
-#define UCIE_TX_DATA_CHUNK_OUT0 0x110ULL
-#define UCIE_TX_DATA_CHUNK_OUT1 0x118ULL
-#define UCIE_TX_TEST_STATE 0x120ULL
-#define UCIE_RX_DATA_MODE 0x128ULL
-#define UCIE_RX_LFSR_SEED 0x130ULL
+#define UCIE_TX_DIVIDER_RST 0xb0ULL
+#define UCIE_RX_DIVIDER_RST 0xb8ULL
+#define UCIE_TX_DATAPATH_RST 0xc0ULL
+#define UCIE_TX_FSM_RST 0xc8ULL
+#define UCIE_TX_EXECUTE 0xd0ULL
+#define UCIE_TX_WRITE_CHUNK 0xd8ULL
+#define UCIE_TX_PACKETS_SENT 0xe0ULL
+#define UCIE_TX_MANUAL_REPEAT_PERIOD 0xe8ULL
+#define UCIE_TX_PACKETS_TO_SEND 0xf0ULL
+#define UCIE_TX_CLK_P 0xf8ULL
+#define UCIE_TX_CLK_N 0x100ULL
+#define UCIE_TX_DATA_LANE_GROUP 0x108ULL
+#define UCIE_TX_DATA_OFFSET 0x110ULL
+#define UCIE_TX_DATA_CHUNK_IN0 0x118ULL
+#define UCIE_TX_DATA_CHUNK_IN1 0x120ULL
+#define UCIE_TX_DATA_CHUNK_OUT0 0x128ULL
+#define UCIE_TX_DATA_CHUNK_OUT1 0x130ULL
+#define UCIE_TX_TEST_STATE 0x138ULL
+#define UCIE_RX_DATA_MODE 0x140ULL
+#define UCIE_RX_LFSR_SEED 0x148ULL
 #define UCIE_RX_LFSR_SEED_WIDTH 0x8ULL
-#define UCIE_RX_BIT_ERRORS 0x1c8ULL
+#define UCIE_RX_BIT_ERRORS 0x1e0ULL
 #define UCIE_RX_BIT_ERRORS_WIDTH 0x8ULL
-#define UCIE_RX_BIT_ERRORS_EARLY 0x260ULL
+#define UCIE_RX_BIT_ERRORS_EARLY 0x278ULL
 #define UCIE_RX_BIT_ERRORS_EARLY_WIDTH 0x8ULL
-#define UCIE_RX_BIT_ERRORS_LATE 0x2f8ULL
+#define UCIE_RX_BIT_ERRORS_LATE 0x310ULL
 #define UCIE_RX_BIT_ERRORS_LATE_WIDTH 0x8ULL
-#define UCIE_RX_RST 0x390ULL
-#define UCIE_RX_PACKETS_TO_RECEIVE 0x398ULL
-#define UCIE_RX_PAUSE_COUNTERS 0x3a0ULL
-#define UCIE_RX_PACKETS_RECEIVED 0x3a8ULL
-#define UCIE_RX_SIGNATURE 0x3b0ULL
-#define UCIE_RX_DATA_LANE 0x3b8ULL
-#define UCIE_RX_DATA_OFFSET 0x3c0ULL
-#define UCIE_RX_DATA_CHUNK 0x3c8ULL
-#define UCIE_CLK_PHASE_SEL 0x3d0ULL
-#define UCIE_CLK_FREQ_SEL 0x3d8ULL
-#define UCIE_TXCTL 0x3e0ULL
+#define UCIE_RX_DATAPATH_RST 0x3a8ULL
+#define UCIE_RX_FSM_RST 0x3b0ULL
+#define UCIE_RX_PACKETS_TO_RECEIVE 0x3b8ULL
+#define UCIE_RX_PAUSE_COUNTERS 0x3c0ULL
+#define UCIE_RX_PACKETS_RECEIVED 0x3c8ULL
+#define UCIE_RX_SIGNATURE 0x3d0ULL
+#define UCIE_RX_IDLE_WORDS_OBSERVED 0x3d8ULL
+#define UCIE_RX_DATA_LANE 0x3e0ULL
+#define UCIE_RX_DATA_OFFSET 0x3e8ULL
+#define UCIE_RX_DATA_CHUNK 0x3f0ULL
+#define UCIE_TXCTL 0x3f8ULL
 #define UCIE_TXCTL_TILE_OFS 0x0ULL
 #define UCIE_TXCTL_SHUFFLER_OFS 0x8ULL
 #define UCIE_TXCTL_SHUFFLER_WIDTH 0x8ULL
 #define UCIE_TXCTL_SAMPLE_NEGEDGE_OFS 0x108ULL
 #define UCIE_TXCTL_DELAY_OFS 0x110ULL
 #define UCIE_TXCTL_WIDTH 0x118ULL
-#define UCIE_RXCTL 0x1ad8ULL
+#define UCIE_RXCTL 0x1af0ULL
 #define UCIE_RXCTL_ZEN_OFS 0x0ULL
 #define UCIE_RXCTL_ZCTL_OFS 0x8ULL
 #define UCIE_RXCTL_VREF_SEL_OFS 0x10ULL
@@ -70,46 +73,146 @@
 #define UCIE_RXCTL_SAMPLE_NEGEDGE_OFS 0x138ULL
 #define UCIE_RXCTL_RX_DELAY_OFS 0x140ULL
 #define UCIE_RXCTL_WIDTH 0x148ULL
-#define UCIE_DEBUG_TX_TEST_MODE 0x35c0ULL
-#define UCIE_DEBUG_TX_DATA_MODE 0x35c8ULL
-#define UCIE_DEBUG_TX_LFSR_SEED 0x35d0ULL
-#define UCIE_DEBUG_TX_FSM_RST 0x35d8ULL
-#define UCIE_DEBUG_TX_EXECUTE 0x35e0ULL
-#define UCIE_DEBUG_TX_MANUAL_REPEAT_PERIOD 0x35e8ULL
-#define UCIE_DEBUG_TX_PACKETS_TO_SEND 0x35f0ULL
-#define UCIE_DEBUG_DATA 0x35f8ULL
+#define UCIE_DEBUG_TX_TEST_MODE 0x35d8ULL
+#define UCIE_DEBUG_TX_DATA_MODE 0x35e0ULL
+#define UCIE_DEBUG_TX_LFSR_SEED 0x35e8ULL
+#define UCIE_DEBUG_TX_FSM_RST 0x35f0ULL
+#define UCIE_DEBUG_TX_EXECUTE 0x35f8ULL
+#define UCIE_DEBUG_TX_MANUAL_REPEAT_PERIOD 0x3600ULL
+#define UCIE_DEBUG_TX_PACKETS_TO_SEND 0x3608ULL
+#define UCIE_DEBUG_DATA 0x3610ULL
 #define UCIE_DEBUG_DATA_WIDTH 0x8ULL
-#define UCIE_DEBUG_DRIVERCTL 0x3678ULL
+#define UCIE_DEBUG_DRIVERCTL 0x3690ULL
 #define UCIE_DEBUG_DRIVERCTL_WIDTH 0x8ULL
-#define UCIE_DEBUG_TXCTL_TILE 0x3698ULL
-#define UCIE_DEBUG_TXCTL_SHUFFLER 0x36a0ULL
+#define UCIE_DEBUG_TXCTL_TILE 0x36b0ULL
+#define UCIE_DEBUG_TXCTL_SHUFFLER 0x36b8ULL
 #define UCIE_DEBUG_TXCTL_SHUFFLER_WIDTH 0x8ULL
-#define UCIE_DEBUG_TX_TEST_STATE 0x37a0ULL
-#define UCIE_DEBUG_TX_PACKETS_SENT 0x37a8ULL
-#define UCIE_DEBUG_CLK_MUX_SEL 0x37b0ULL
-#define UCIE_DEBUG_RX_LANE 0x37b8ULL
-#define UCIE_DEBUG_RX_BIT 0x37c0ULL
-#define UCIE_TX_VALID 0x37c8ULL
-#define UCIE_RX_LFSR_VALID 0x37d0ULL
-#define UCIE_CONTROLLER_SEL 0x37d8ULL
-#define UCIE_MAINBAND_MODE 0x37e0ULL
-#define UCIE_SIDEBAND_MODE 0x37e8ULL
-#define UCIE_CREDIT_FLOW_ENABLE 0x37f0ULL
-#define UCIE_TX_VALID_LANE_SEL 0x37f8ULL
-#define UCIE_RX_VALID_LANE_SEL 0x3800ULL
-#define UCIE_LAST_SEEN_TL_REQ 0x3808ULL
-#define UCIE_SB_TX_PACKET 0x3810ULL
-#define UCIE_SB_TX_SEND 0x3818ULL
-#define UCIE_SB_TX_BUSY 0x3820ULL
-#define UCIE_SB_RX_PACKET 0x3828ULL
-#define UCIE_SB_RX_VALID 0x3830ULL
-#define UCIE_SB_RX_POP 0x3838ULL
-#define UCIE_SB_RX_OVERFLOW 0x3840ULL
-#define UCIE_SB_RX_RST 0x3848ULL
-#define UCIE_SB_TL_RX_OVERFLOW 0x3850ULL
-#define UCIE_UCIE_LINK_RESET 0x3858ULL
-#define UCIE_UCIE_PWR_GOOD 0x3860ULL
-#define UCIE_UCIE_RETRY_TRAINING_AMT 0x3868ULL
+#define UCIE_DEBUG_TX_TEST_STATE 0x37b8ULL
+#define UCIE_DEBUG_TX_PACKETS_SENT 0x37c0ULL
+#define UCIE_DEBUG_CLK_MUX_SEL 0x37c8ULL
+#define UCIE_DEBUG_RX_LANE 0x37d0ULL
+#define UCIE_DEBUG_RX_BIT 0x37d8ULL
+#define UCIE_TX_VALID 0x37e0ULL
+#define UCIE_RX_LFSR_VALID 0x37e8ULL
+#define UCIE_CONTROLLER_SEL 0x37f0ULL
+#define UCIE_MAINBAND_MODE 0x37f8ULL
+#define UCIE_SIDEBAND_MODE 0x3800ULL
+#define UCIE_CREDIT_FLOW_ENABLE 0x3808ULL
+#define UCIE_TX_VALID_LANE_SEL 0x3810ULL
+#define UCIE_RX_VALID_LANE_SEL 0x3818ULL
+#define UCIE_LAST_SEEN_TL_REQ 0x3820ULL
+#define UCIE_SB_TX_PACKET 0x3828ULL
+#define UCIE_SB_TX_SEND 0x3830ULL
+#define UCIE_SB_TX_BUSY 0x3838ULL
+#define UCIE_SB_RX_PACKET 0x3840ULL
+#define UCIE_SB_RX_VALID 0x3848ULL
+#define UCIE_SB_RX_POP 0x3850ULL
+#define UCIE_SB_RX_OVERFLOW 0x3858ULL
+#define UCIE_SB_RX_RST 0x3860ULL
+#define UCIE_SB_TL_RX_OVERFLOW 0x3868ULL
+#define UCIE_PCIE_EXT_CAP_ID 0x4000ULL
+#define UCIE_DVSEC_VENDOR_ID 0x4004ULL
+#define UCIE_DVSEC_ID 0x4008ULL
+#define UCIE_RAW_FORMAT 0x400cULL
+#define UCIE_RAW_FORMAT_ENABLE 0x4010ULL
+#define UCIE_RAW_FORMAT_ENABLED 0x4014ULL
+#define UCIE_LINK_STATUS_CHANGED_INT_EN 0x4018ULL
+#define UCIE_LOCATOR0_BIR 0x401cULL
+#define UCIE_LOCATOR0_BLOCK_OFFSET_HI 0x4020ULL
+#define UCIE_LOCATOR1_BIR 0x4024ULL
+#define UCIE_LOCATOR1_BLOCK_OFFSET_HI 0x4028ULL
+#define UCIE_MAILBOX_OPCODE 0x402cULL
+#define UCIE_MAILBOX_ADDR_HI 0x4030ULL
+#define UCIE_MAILBOX_DATA_LO 0x4034ULL
+#define UCIE_MAILBOX_DATA_HI 0x4038ULL
+#define UCIE_MAILBOX_TRIGGER 0x403cULL
+#define UCIE_MAILBOX_STATUS 0x4040ULL
+#define UCIE_VENDOR_ID 0x5000ULL
+#define UCIE_VENDOR_REG_BLOCK_VERSION 0x5004ULL
+#define UCIE_VENDOR_REG_BLOCK_LENGTH 0x5008ULL
+#define UCIE_VENDOR_REG_BLOCK_RESERVED 0x500cULL
+#define UCIE_UNCORR_ERR_STATUS 0x5010ULL
+#define UCIE_UNCORR_ERR_MASK 0x5014ULL
+#define UCIE_UNCORR_ERR_SEVERITY 0x5018ULL
+#define UCIE_CORR_ERR_STATUS 0x501cULL
+#define UCIE_CORR_ERR_MASK 0x5020ULL
+#define UCIE_HEADER_LOG1_LO 0x5024ULL
+#define UCIE_HEADER_LOG1_HI 0x5028ULL
+#define UCIE_HL2_TIMEOUT_ENC 0x502cULL
+#define UCIE_REMOTE_REG_ACCESS_THRESHOLD 0x5030ULL
+#define UCIE_PARITY_LOG0_LO 0x5034ULL
+#define UCIE_PARITY_LOG0_HI 0x5038ULL
+#define UCIE_PARITY_LOG1_LO 0x503cULL
+#define UCIE_PARITY_LOG1_HI 0x5040ULL
+#define UCIE_PARITY_LOG2_LO 0x5044ULL
+#define UCIE_PARITY_LOG2_HI 0x5048ULL
+#define UCIE_PARITY_LOG3_LO 0x504cULL
+#define UCIE_PARITY_LOG3_HI 0x5050ULL
+#define UCIE_ADV_ADAPTER_CAP_LO 0x5054ULL
+#define UCIE_ADV_ADAPTER_CAP_HI 0x5058ULL
+#define UCIE_FIN_ADAPTER_CAP_LO 0x505cULL
+#define UCIE_FIN_ADAPTER_CAP_HI 0x5060ULL
+#define UCIE_ADV_CXL_CAP_LO 0x5064ULL
+#define UCIE_ADV_CXL_CAP_HI 0x5068ULL
+#define UCIE_FIN_CXL_CAP_LO 0x506cULL
+#define UCIE_FIN_CXL_CAP_HI 0x5070ULL
+#define UCIE_ADV_MULTIPROT_CAP_LO 0x5078ULL
+#define UCIE_ADV_MULTIPROT_CAP_HI 0x507cULL
+#define UCIE_FIN_MULTIPROT_CAP_LO 0x5080ULL
+#define UCIE_FIN_MULTIPROT_CAP_HI 0x5084ULL
+#define UCIE_ADV_CXL_CAP_STACK1_LO 0x5088ULL
+#define UCIE_ADV_CXL_CAP_STACK1_HI 0x508cULL
+#define UCIE_FIN_CXL_CAP_STACK1_LO 0x5090ULL
+#define UCIE_FIN_CXL_CAP_STACK1_HI 0x5094ULL
+#define UCIE_PHY_CAP_RSVD 0x6000ULL
+#define UCIE_PHY_CTRL_RSVD 0x6004ULL
+#define UCIE_PHY_STATUS_RSVD 0x6008ULL
+#define UCIE_INIT_CONTROL 0x600cULL
+#define UCIE_RLT_CTRL 0x6100ULL
+#define UCIE_MODULE3_LANE_REPAIR_ID_RSVD_HI 0x6104ULL
+#define UCIE_RUNTIME_LINK_TEST_BUSY 0x6108ULL
+#define UCIE_NULL_EXT_CAP 0x6200ULL
+#define UCIE_TS1_DATA_PATTERN_M0 0x6010ULL
+#define UCIE_TS2_IDLE_COUNT_M0 0x6020ULL
+#define UCIE_TS3_LANE_MASK_LO_M0 0x6030ULL
+#define UCIE_TS3_LANE_MASK_HI_M0 0x6034ULL
+#define UCIE_TS4_REPAIR_LANE_MASK_M0 0x6050ULL
+#define UCIE_CURRENT_LANE_MAP_LO_M0 0x6060ULL
+#define UCIE_CURRENT_LANE_MAP_HI_M0 0x6064ULL
+#define UCIE_ERR_LOG0_STATE_NM0 0x6080ULL
+#define UCIE_ERR_LOG1_STATE_NM3_M0 0x6090ULL
+#define UCIE_VENDOR_REG_BLOCK_RSVD 0x700cULL
+#define UCIE_VENDOR_DEBUG_UNLOCK 0x7010ULL
+#define UCIE_VENDOR_FORCE_LINK_ACTIVE 0x7014ULL
+#define UCIE_VENDOR_TS_OVERRIDE_EN 0x7018ULL
+#define UCIE_UCIE_LINK_RESET 0x3c00ULL
+#define UCIE_UCIE_PWR_GOOD 0x3c08ULL
+#define UCIE_UCIE_RETRY_TRAINING_AMT 0x3c10ULL
+#define UCIE_MAIN_CLK_SEL 0x10000ULL
+#define UCIE_PLL8_EN 0x10008ULL
+#define UCIE_PLL12_EN 0x10010ULL
+#define UCIE_X2_EN 0x10018ULL
+#define UCIE_TX_CLK_DIV 0x10020ULL
+#define UCIE_TX_CLK_PHASE 0x10028ULL
+#define UCIE_PHY_TEST_CLK_DIV 0x10030ULL
+#define UCIE_PHY_TEST_CLK_BYPASS_EN 0x10038ULL
+#define UCIE_CLK_PHASE_SEL 0x10040ULL
+#define UCIE_CLK_GATE_EN 0x10048ULL
+#define UCIE_RX_CLK_GATE_EN 0x10050ULL
+#define UCIE_FREQ_SEL_AUTO_EN 0x10058ULL
+#define UCIE_FREQ_SEL_OBSERVED 0x10060ULL
+#define UCIE_SB_CLK_DIV 0x10068ULL
+#define UCIE_SB_CLK_BYPASS_EN 0x10070ULL
+#define UCIE_RX_CLK_FROM_TX_Q 0x10078ULL
+#define UCIE_CLK_CFG_APPLY 0x10080ULL
+#define UCIE_CLK_CFG_BUSY 0x10088ULL
+#define UCIE_CLK_CFG_UNGATE_SRC 0x10090ULL
+#define UCIE_CLK_CFG_UNGATE_DELAY 0x10098ULL
+#define UCIE_CLK_CFG_UNGATE_REQ 0x100a0ULL
+#define UCIE_PLL_LOCK_OBSERVED 0x100a8ULL
+#define UCIE_UCIE_RST 0x100b0ULL
+#define UCIE_RATE_CFG 0x10100ULL
+#define UCIE_RATE_CFG_WIDTH 0x8ULL
 
 // === Constants ===
 #define UCIE_TX_TEST_STATE_IDLE 0x0ULL
@@ -130,12 +233,43 @@
 #define UCIE_DEFAULT_VALID 0xf0f0f0fULL
 #define UCIE_DEFAULT_TRACK 0x55555555ULL
 #define UCIE_ENABLE_DRIVER_CTL 0x3ffeULL
-#define UCIE_ENABLE_TX_CTL 0x1fff000000000ULL
+#define UCIE_ENABLE_TX_CTL 0x3fffff000000000ULL
+#define UCIE_TX_CTL_DELAY_LSB 0x0ULL
+#define UCIE_TX_CTL_ENP_LSB 0x31ULL
+#define UCIE_TX_CTL_ENN_LSB 0x28ULL
+#define UCIE_TX_CTL_ENP_EQ_LSB 0x24ULL
+#define UCIE_TX_CTL_ENN_EQ_LSB 0x20ULL
+#define UCIE_TRAIN_LFSR_SEED 0x123456789abcdefULL
+#define UCIE_TRAIN_DATA_LANES 0x10ULL
+#define UCIE_TRAIN_VALID_LANE 0x10ULL
+#define UCIE_TRAIN_SCORE_LANES 0x11ULL
+#define UCIE_RATE_CFG_MAIN_CLK_SEL_LSB 0x8ULL
+#define UCIE_RATE_CFG_TX_CLK_DIV_LSB 0x6ULL
+#define UCIE_RATE_CFG_PHY_TEST_CLK_DIV_LSB 0x3ULL
+#define UCIE_TRAIN_EYE_FINE_POINTS 0x4ULL
+#define UCIE_TRAIN_EYE_FINE_STEP 0x10ULL
+#define UCIE_TRAIN_EYE_DIVS 0x3ULL
+#define UCIE_TRAIN_GLOBAL_CODES 0x10ULL
+#define UCIE_TRAIN_GLOBAL_STEP 0x4ULL
+#define UCIE_TRAIN_LOCAL_CODES 0x10ULL
+#define UCIE_TRAIN_LOCAL_STEP 0x2ULL
+#define UCIE_TRAIN_VREF_CODES 0x10ULL
+#define UCIE_TRAIN_VREF_STEP 0x8ULL
+#define UCIE_TRAIN_PACKETS 0x10ULL
+#define UCIE_TRAIN_SLIP_RATIO 0x4ULL
+#define UCIE_CLK_UNGATE_SRC_PLL_LOCK 0x0ULL
+#define UCIE_CLK_UNGATE_SRC_MMIO 0x1ULL
+#define UCIE_CLK_UNGATE_SRC_DELAY 0x2ULL
 
 // === Helper functions ===
+static inline void reset_datapath(uintptr_t base) {
+  reg_write64(base + UCIE_TX_DATAPATH_RST, 0x1ULL);
+  reg_write64(base + UCIE_RX_DATAPATH_RST, 0x1ULL);
+}
 static inline void reset_fsms(uintptr_t base) {
-  reg_write64(base + UCIE_TX_RST, 0x1ULL);
-  reg_write64(base + UCIE_RX_RST, 0x1ULL);
+  reset_datapath(base);
+  reg_write64(base + UCIE_TX_FSM_RST, 0x1ULL);
+  reg_write64(base + UCIE_RX_FSM_RST, 0x1ULL);
   reg_write64(base + UCIE_DEBUG_TX_FSM_RST, 0x1ULL);
   assert(reg_read64(base + UCIE_TX_TEST_STATE) == (UCIE_TX_TEST_STATE_IDLE));
   assert(reg_read64(base + UCIE_TX_PACKETS_SENT) == (0x0ULL));
@@ -150,7 +284,77 @@ static inline void write_rxctl(uintptr_t base, uint64_t lane, uint64_t ofs, uint
   reg_write64(base + UCIE_RXCTL + lane * UCIE_RXCTL_WIDTH + ofs, v);
 }
 
+static inline void set_clk_gate(uintptr_t base, uint64_t en) {
+  reg_write64(base + UCIE_CLK_GATE_EN, en);
+}
+static inline void set_rate_cfg(uintptr_t base, uint64_t rate, uint64_t main_sel, uint64_t tx_div, uint64_t phytest_div, uint64_t pll_en) {
+  reg_write64(base + UCIE_RATE_CFG + rate * UCIE_RATE_CFG_WIDTH, ((main_sel << UCIE_RATE_CFG_MAIN_CLK_SEL_LSB) | (tx_div << UCIE_RATE_CFG_TX_CLK_DIV_LSB) | (phytest_div << UCIE_RATE_CFG_PHY_TEST_CLK_DIV_LSB) | pll_en));
+}
+static inline void set_freq_sel_auto(uintptr_t base, uint64_t en) {
+  reg_write64(base + UCIE_FREQ_SEL_AUTO_EN, en);
+}
+static inline void apply_clk_cfg(uintptr_t base) {
+  reg_write64(base + UCIE_CLK_CFG_APPLY, 0x1ULL);
+  for (int w = 0; w < 256; w++) {
+    uint64_t busy;
+    busy = reg_read64(base + UCIE_CLK_CFG_BUSY);
+    if (busy == 0) {
+      break;
+    }
+  }
+}
+static inline void set_ungate_src(uintptr_t base, uint64_t src, uint64_t delay) {
+  reg_write64(base + UCIE_CLK_CFG_UNGATE_SRC, src);
+  reg_write64(base + UCIE_CLK_CFG_UNGATE_DELAY, delay);
+}
+static inline void release_clk_gate(uintptr_t base) {
+  reg_write64(base + UCIE_CLK_CFG_UNGATE_REQ, 0x1ULL);
+}
+static inline void reset_ucie(uintptr_t base) {
+  reg_write64(base + UCIE_UCIE_RST, 0x1ULL);
+  reg_write64(base + UCIE_UCIE_RST, 0x0ULL);
+}
+static inline void reset_dividers(uintptr_t base) {
+  reg_write64(base + UCIE_TX_DIVIDER_RST, 0x1ULL);
+  reg_write64(base + UCIE_RX_DIVIDER_RST, 0x1ULL);
+  reg_write64(base + UCIE_TX_DIVIDER_RST, 0x0ULL);
+  reg_write64(base + UCIE_RX_DIVIDER_RST, 0x0ULL);
+}
+static inline void set_main_clk(uintptr_t base, uint64_t src, uint64_t div) {
+  reg_write64(base + UCIE_MAIN_CLK_SEL, src);
+  reg_write64(base + UCIE_TX_CLK_DIV, div);
+  reg_write64(base + UCIE_CLK_GATE_EN, 0x1ULL);
+  apply_clk_cfg(base);
+}
+static inline void set_tx_phase(uintptr_t base, uint64_t half_cycles) {
+  reg_write64(base + UCIE_CLK_GATE_EN, 0x0ULL);
+  reg_write64(base + UCIE_TX_CLK_PHASE, half_cycles);
+  reg_write64(base + UCIE_CLK_GATE_EN, 0x1ULL);
+}
+static inline void use_internal_clk(uintptr_t base, uint64_t phytest_div) {
+  reg_write64(base + UCIE_PLL8_EN, 0x1ULL);
+  reg_write64(base + UCIE_PLL12_EN, 0x1ULL);
+  reg_write64(base + UCIE_X2_EN, 0x1ULL);
+  reg_write64(base + UCIE_PHY_TEST_CLK_DIV, phytest_div);
+  reg_write64(base + UCIE_PHY_TEST_CLK_BYPASS_EN, 0x0ULL);
+  apply_clk_cfg(base);
+}
+static inline void set_rx_clk_gate(uintptr_t base, uint64_t en) {
+  reg_write64(base + UCIE_RX_CLK_GATE_EN, en);
+}
+static inline void set_global_delay(uintptr_t base, uint64_t taps) {
+  reg_write64(base + UCIE_CLK_PHASE_SEL, ((0x1ULL << taps) - 0x1ULL));
+}
+static inline void set_tx_delay(uintptr_t base, uint64_t lane, uint64_t taps) {
+  write_txctl(base, lane, UCIE_TXCTL_TILE_OFS, (UCIE_ENABLE_TX_CTL | (((0x1ULL << taps) - 0x1ULL) << UCIE_TX_CTL_DELAY_LSB)));
+}
+
+static inline void set_rx_vref(uintptr_t base, uint64_t lane, uint64_t code) {
+  write_rxctl(base, lane, UCIE_RXCTL_VREF_SEL_OFS, code);
+}
+
 static inline void setup_ucie(uintptr_t base) {
+  reset_ucie(base);
   for (int lane = 0; lane < 21; lane++) {
     write_txctl(base, lane, UCIE_TXCTL_TILE_OFS, UCIE_ENABLE_TX_CTL);
     write_rxctl(base, lane, UCIE_RXCTL_ZEN_OFS, 0x1ULL);
@@ -164,10 +368,75 @@ static inline void setup_ucie(uintptr_t base) {
     reg_write64(base + UCIE_DEBUG_DRIVERCTL + 8 * i, UCIE_ENABLE_DRIVER_CTL);
   }
   reg_write64(base + UCIE_DEBUG_TXCTL_TILE, UCIE_ENABLE_TX_CTL);
-  reset_fsms(base);
+  set_clk_gate(base, 0x0ULL);
+  reset_dividers(base);
+  set_clk_gate(base, 0x1ULL);
   reg_write64(base + UCIE_CONTROLLER_SEL, UCIE_CONTROLLER_SEL_PHYTEST);
   reg_write64(base + UCIE_MAINBAND_MODE, UCIE_BAND_MODE_MANUAL);
   reg_write64(base + UCIE_SIDEBAND_MODE, UCIE_BAND_MODE_MANUAL);
+  reset_fsms(base);
+}
+
+static inline void setup_ucie_digital(uintptr_t base) {
+  set_clk_gate(base, 0x0ULL);
+  set_global_delay(base, 0x1dULL);
+  reset_dividers(base);
+  set_clk_gate(base, 0x1ULL);
+  for (int lane = 0; lane < 20; lane++) {
+    write_txctl(base, lane, UCIE_TXCTL_TILE_OFS, UCIE_ENABLE_TX_CTL);
+  }
+  for (int lane = 0; lane < 18; lane++) {
+    write_rxctl(base, lane, UCIE_RXCTL_ZEN_OFS, 0x1ULL);
+    write_rxctl(base, lane, UCIE_RXCTL_ZCTL_OFS, 0x0ULL);
+  }
+  reg_write64(base + UCIE_CONTROLLER_SEL, UCIE_CONTROLLER_SEL_UCIE);
+  reset_datapath(base);
+  {
+    uint64_t linkControl;
+    linkControl = reg_read64(base + UCIE_RAW_FORMAT_ENABLE);
+    reg_write64(base + UCIE_RAW_FORMAT_ENABLE, linkControl | 0x401ULL);
+  }
+  reg_write64(base + UCIE_UNCORR_ERR_MASK, 0x0ULL);
+  reg_write64(base + UCIE_CORR_ERR_MASK, 0x0ULL);
+  while (1) {
+    uint64_t linkStatus;
+    linkStatus = reg_read64(base + UCIE_RAW_FORMAT_ENABLED);
+    if ((linkStatus >> 0xfULL) & 0x1ULL) {
+      break;
+    }
+  }
+}
+
+static inline void seed_lfsrs(uintptr_t base) {
+  for (int i = 0; i < 19; i++) {
+    reg_write64(base + UCIE_TX_LFSR_SEED + i * UCIE_TX_LFSR_SEED_WIDTH, UCIE_TRAIN_LFSR_SEED);
+    reg_write64(base + UCIE_RX_LFSR_SEED + i * UCIE_RX_LFSR_SEED_WIDTH, UCIE_TRAIN_LFSR_SEED);
+  }
+}
+
+static inline void run_lfsr(uintptr_t base, uint64_t packets) {
+  reset_fsms(base);
+  for (int s = 0; s < 64; s++) {
+    uint64_t settle_w;
+    settle_w = reg_read64(base + UCIE_RX_IDLE_WORDS_OBSERVED);
+    if (settle_w >= 4) {
+      break;
+    }
+  }
+  reg_write64(base + UCIE_TEST_TARGET, UCIE_TEST_TARGET_MAINBAND);
+  reg_write64(base + UCIE_TX_TEST_MODE, UCIE_TX_TEST_MODE_LFSR);
+  reg_write64(base + UCIE_TX_DATA_MODE, UCIE_DATA_MODE_FINITE);
+  reg_write64(base + UCIE_RX_DATA_MODE, UCIE_DATA_MODE_FINITE);
+  reg_write64(base + UCIE_RX_PACKETS_TO_RECEIVE, packets);
+  reg_write64(base + UCIE_TX_PACKETS_TO_SEND, packets);
+  reg_write64(base + UCIE_TX_EXECUTE, 0x1ULL);
+  for (int w = 0; w < 16; w++) {
+    uint64_t r;
+    r = reg_read64(base + UCIE_RX_PACKETS_RECEIVED);
+    if (r >= packets) {
+      break;
+    }
+  }
 }
 
 #endif
diff --git a/src/Iris.scala b/src/Iris.scala
index e4eb9af..85abb95 100644
--- a/src/Iris.scala
+++ b/src/Iris.scala
@@ -29,6 +29,8 @@ import freechips.rocketchip.subsystem._
 import freechips.rocketchip.prci._
 import freechips.rocketchip.devices.debug._
 import freechips.rocketchip.devices.tilelink.BootROMLocated
+import freechips.rocketchip.tilelink.{TLBuffer, TLFragmenter, TLWidthWidget}
+import edu.berkeley.cs.uciedigital.tilelink.UcieChipletLink
 import freechips.rocketchip.util._
 import sifive.blocks.inclusivecache.{InclusiveCachePortParameters}
 
@@ -63,6 +65,20 @@ class IrisTop(implicit p: Parameters) extends LazyModule with BindingScope {
     .fixedClockNode
   def debugClockBundle = debugClockSinkNode.in.head._1
 
+  // Each UCIe link's register port, on the chiplet router's control bus. The
+  // router cannot attach these itself: each is a crossbar in front of UcieTL's
+  // register blocks, not the bare register node it takes.
+  system.d2d_ports.foreach { ports =>
+    val cbus = system.locateTLBusWrapper(p(ChipletRoutingKey).get.controlBusWhere)
+    val links = ports.collect { case link: UcieChipletLink => link }
+    links.foreach { link =>
+      cbus.coupleTo(s"${link.name}_control") {
+        link.regNode := TLWidthWidget(cbus.beatBytes) := TLBuffer() :=
+          TLFragmenter(cbus) := _
+      }
+    }
+  }
+
   override lazy val module = new IrisTopImpl
   class IrisTopImpl extends LazyRawModuleImp(this) with DontTouch {
     val io = IO(new Bundle {
@@ -130,7 +146,7 @@ class IrisTop(implicit p: Parameters) extends LazyModule with BindingScope {
 // IrisConfig and IrisDryRunConfig differ only in
 //   * the SBUS NoC node mapping, and
 //   * which optional blocks are present: the Rocket Saturn DMA vector unit, the
-//     two Shuttle tiles with their Saturn OPU, and the UCIe chiplet router.
+//     Shuttle tile with its Saturn OPU, and the UCIe chiplet router.
 // Everything else is identical and lives in the fragments below.
 //
 // These are several fragments rather than one block because CDE composition is
@@ -140,8 +156,8 @@ class IrisTop(implicit p: Parameters) extends LazyModule with BindingScope {
 //     sit to the LEFT of WithIrisRocketCore.
 //   * The Shuttle fragments must sit to the RIGHT of WithIrisRocketCore. Tile
 //     ids are handed out from `up(NumTiles)`, so this ordering is what makes the
-//     Shuttle tiles harts 0-1 and Rocket hart 2 -- which the NoC mapping keys
-//     off by name ("Core 0 ICache", "Core 2 DCache").
+//     Shuttle tile hart 0 and Rocket hart 1 -- which the NoC mapping keys
+//     off by name ("Core 0 ICache", "Core 1 DCache").
 // ============================================================================
 
 /** SBUS NoC parameters. Only the node mapping differs between the two chips;
diff --git a/src/TinyIris.scala b/src/TinyIris.scala
index 94a0de6..6243c35 100644
--- a/src/TinyIris.scala
+++ b/src/TinyIris.scala
@@ -29,6 +29,8 @@ import freechips.rocketchip.subsystem._
 import freechips.rocketchip.prci._
 import freechips.rocketchip.devices.debug._
 import freechips.rocketchip.devices.tilelink.BootROMLocated
+import freechips.rocketchip.tilelink.{TLBuffer, TLFragmenter, TLWidthWidget}
+import edu.berkeley.cs.uciedigital.tilelink.UcieChipletLink
 import freechips.rocketchip.util._
 import sifive.blocks.inclusivecache.{InclusiveCachePortParameters}
 
@@ -44,6 +46,20 @@ class TinyIrisTop(implicit p: Parameters) extends LazyModule with BindingScope {
     .fixedClockNode
   def debugClockBundle = debugClockSinkNode.in.head._1
 
+  // Each UCIe link's register port, on the chiplet router's control bus. The
+  // router cannot attach these itself: each is a crossbar in front of UcieTL's
+  // register blocks, not the bare register node it takes.
+  system.d2d_ports.foreach { ports =>
+    val cbus = system.locateTLBusWrapper(p(ChipletRoutingKey).get.controlBusWhere)
+    val links = ports.collect { case link: UcieChipletLink => link }
+    links.foreach { link =>
+      cbus.coupleTo(s"${link.name}_control") {
+        link.regNode := TLWidthWidget(cbus.beatBytes) := TLBuffer() :=
+          TLFragmenter(cbus) := _
+      }
+    }
+  }
+
   override lazy val module = new IrisTopImpl
   class IrisTopImpl extends LazyRawModuleImp(this) with DontTouch {
     val io = IO(new Bundle {
diff --git a/test/src/IrisSpec.scala b/test/src/IrisSpec.scala
index da209de..01ca0c0 100644
--- a/test/src/IrisSpec.scala
+++ b/test/src/IrisSpec.scala
@@ -141,28 +141,21 @@ class TestHarness(nChips: Int, binaryPaths: Seq[Path], plusArgs: Seq[Seq[String]
     val reset = Input(Bool())
   })
 
-  val digitalFreqMHz = 500
-
-  val digitalClock = Wire(Clock())
-  val source = Module(new ClockSourceAtFreqMHz(digitalFreqMHz))
-  source.io.power := true.B
-  source.io.gate := false.B
-  digitalClock := source.io.clk
-
-  val ucieBypassFreqMHz = 8000
-  val ucieBypassClock = Wire(Clock())
-  val ucieBypassClockSource = Module(new ClockSourceAtFreqMHz(ucieBypassFreqMHz))
-  ucieBypassClockSource.io.power := true.B
-  ucieBypassClockSource.io.gate := false.B
-  ucieBypassClock := ucieBypassClockSource.io.clk
-
-  val ucieDigitalBypassFreqMHz = 800
-  val ucieDigitalBypassClock = Wire(Clock())
-  val ucieDigitalBypassClockSource = Module(new ClockSourceAtFreqMHz(ucieDigitalBypassFreqMHz))
-  ucieDigitalBypassClockSource.io.power := true.B
-  ucieDigitalBypassClockSource.io.gate := false.B
-  ucieDigitalBypassClock := ucieDigitalBypassClockSource.io.clk
+  // A free-running clock from a simulation clock source.
+  def freeRunningClock(freqMHz: Double): Clock = {
+    val source = Module(new ClockSourceAtFreqMHz(freqMHz))
+    source.io.power := true.B
+    source.io.gate := false.B
+    source.io.clk
+  }
 
+  val digitalFreqMHz = 500
+  val digitalClock = freeRunningClock(digitalFreqMHz)
+  val ucieBypassClock = freeRunningClock(8000)
+  val ucieDigitalBypassClock = freeRunningClock(800)
+  val ucieSidebandBypassClock = freeRunningClock(800)
+  // The clocking tile's PLL reference, as in the UCIe repo's own harness.
+  val ucieRefClock = freeRunningClock(100)
 
   implicit def view[A <: Data, B <: Data]
       : DataView[testchipip.tsi.TSIIO, TSIIO] =
@@ -228,6 +221,8 @@ class TestHarness(nChips: Int, binaryPaths: Seq[Path], plusArgs: Seq[Seq[String]
     Seq(chiptop.c2c_ucie0, chiptop.c2c_ucie1).foreach { ucie =>
       ucie.phy.bypassClk := ucieBypassClock
       ucie.phy.digitalBypassClk := ucieDigitalBypassClock
+      ucie.phy.sidebandBypassClk := ucieSidebandBypassClock
+      ucie.phy.refClk := ucieRefClock
     }
 
     Seq(chiptop.c2c_ucie0, chiptop.c2c_ucie1)
diff --git a/test/src/Utils.scala b/test/src/Utils.scala
index f58f577..c14f89f 100644
--- a/test/src/Utils.scala
+++ b/test/src/Utils.scala
@@ -52,7 +52,7 @@ verilator \\
   -CFLAGS "$$CXXFLAGS -O3 -std=c++17 -DVERILATOR -I$$RISCV/include" \\
   -LDFLAGS "$$LDFLAGS -L$$RISCV/lib -Wl,-rpath,$$RISCV/lib -lriscv -lfesvr" \\
   -F ${sourceFilesList.toString}
-script -f -c "./simulation </dev/null 2> >(spike-dasm > simulation.out)" simulation.log
+script -e -f -c "./simulation </dev/null 2> >(spike-dasm > simulation.out)" simulation.log
 """
     )
     path.toIO.setExecutable(true)
@@ -89,7 +89,7 @@ vcs \\
   +define+layer$$Verification$$Cover$$Temporal \\
   +define+VCS +define+FSDB +define+RANDOMIZE_MEM_INIT +define+RANDOMIZE_REG_INIT +define+RANDOMIZE_GARBAGE_ASSIGN +define+RANDOMIZE_INVALID_ASSIGN$debugCompileFlags \\
   -o simulation -Mdir=vcs-sources
-script -f -c "./simulation +permissive +vcs+thread+16 +dramsim +dramsim_ini_dir=${dramsim_ini.toString}${loadmem.map(p => s" +loadmem=${p.toString}").getOrElse("")}$debugRuntimeFlag +permissive-off placeholder-binary </dev/null 2> >(spike-dasm > simulation.out)" simulation.log
+script -e -f -c "./simulation +permissive +vcs+thread+16 +dramsim +dramsim_ini_dir=${dramsim_ini.toString}${loadmem.map(p => s" +loadmem=${p.toString}").getOrElse("")}$debugRuntimeFlag +permissive-off placeholder-binary </dev/null 2> >(spike-dasm > simulation.out)" simulation.log
 """
     )
     path.toIO.setExecutable(true)
@@ -162,5 +162,19 @@ script -f -c "./simulation +permissive +vcs+thread+16 +dramsim +dramsim_ini_dir=
       "/bin/bash",
       simScript
     ).call(stdout = os.Inherit, stderr = os.Inherit, cwd = simDir)
+
+    // The simulator's exit status does not say whether the test passed: VCS
+    // ends with status 0 after a `$fatal`, whether from SimTop's timeout or
+    // from a failed assertion. SimTop prints its success line only when the
+    // chips report success, so the log decides it.
+    val simLog = os.read(simDir / "simulation.log")
+    val failure =
+      Seq("Assertion failed", "Fatal:", "Test timed out!").find(simLog.contains)
+    assert(
+      failure.isEmpty && simLog.contains("Test completed successfully."),
+      failure.fold("simulation ended without reporting success")(f =>
+        s"simulation log reports \"$f\""
+      ) + s"; see ${simDir / "simulation.log"}"
+    )
   }
 }
diff --git a/testchipip b/testchipip
index fc8013c..86c9a82 160000
--- a/testchipip
+++ b/testchipip
@@ -1 +1 @@
-Subproject commit fc8013c30e098f46402f1c98543b9d4b7b9b36d2
+Subproject commit 86c9a824fd42b854526018f9111087b0f3d1d31c
diff --git a/ucie b/ucie
index caf0daf..4db6449 160000
--- a/ucie
+++ b/ucie
@@ -1 +1 @@
-Subproject commit caf0daf1135f5b87225fa4903fcc3dfb87863de5
+Subproject commit 4db6449716976a79765828a6dc27547c6a0c6366