diff --git a/src/libboard_artiq/src/cxp_upconn.rs b/src/libboard_artiq/src/cxp_upconn.rs
index f7158ac..63ce128 100644
--- a/src/libboard_artiq/src/cxp_upconn.rs
+++ b/src/libboard_artiq/src/cxp_upconn.rs
@@ -47,13 +47,7 @@ pub fn pipeline_test(timer: &mut GlobalTimer) {
 }
 
 pub fn tx_test(timer: &mut GlobalTimer) {
-    // the 8bit shift is k symbol
-    // const K28_1: u16 = 0x3C | (1 << 8);
-    // const K28_5: u16 = 0xBC | (1 << 8);
-    const D01_1: u16 = 0x21;
-    const D31_1: u16 = 0x3F;
-
-    const LEN: usize = 4 * 100;
+    const LEN: usize = 4 * 30;
     let mut pak_arr: [u8; LEN] = [0; LEN];
 
     unsafe {
@@ -64,17 +58,20 @@ pub fn tx_test(timer: &mut GlobalTimer) {
 
             // TODO: verify the char & word boundary thingy
             for _ in 0..12 {
-                csr::cxp::upconn_symbol2_write(D31_1);
+                csr::cxp::upconn_symbol2_write(0xFF);
             }
 
             csr::cxp::upconn_tx_enable_write(1);
+            // Give some time for symbol2 to send b4 sending priority zero packet
             timer.delay_us(1);
 
-            for _ in 0..3 {
-                csr::cxp::upconn_symbol0_write(D01_1);
+            for i in 0..6 {
+                csr::cxp::upconn_symbol0_write(i + 1);
             }
-            timer.delay_us(10);
+            timer.delay_us(20);
 
+            csr::cxp::upconn_tx_enable_write(0);
+            // Collect data
             let mut i: usize = 0;
             while csr::cxp::upconn_upconn_phy_debug_buf_dout_valid_read() == 1 {
                 pak_arr[i] = csr::cxp::upconn_upconn_phy_debug_buf_dout_pak_read();
@@ -89,7 +86,8 @@ pub fn tx_test(timer: &mut GlobalTimer) {
             println!("arr = [");
             for i in 0..(LEN / 4) {
                 println!(
-                    "     {:#04X} {:#04X} {:#04X} {:#04X},",
+                    "{:#03}     {:#04X} {:#04X} {:#04X} {:#04X},",
+                    i + 1,
                     pak_arr[i * 4],
                     pak_arr[i * 4 + 1],
                     pak_arr[i * 4 + 2],
@@ -97,47 +95,7 @@ pub fn tx_test(timer: &mut GlobalTimer) {
                 )
             }
             println!("]");
-            // for i in 0..LEN {
-            //     arr[i] = get_encoded();
-            //     // if csr::cxp::upconn_tx_busy_read() == 0 {
-            //     //     break;
-            //     // };
-            // }
-            // let mut last_encoded: u16 = 0;
-            // for i in 0..LEN {
-            //     if last_encoded != arr[i] {
-            //         match arr[i] {
-            //             0b1010111001 | 0b0101001001 => {
-            //                 println!("D31.1")
-            //             }
-            //             0b0111011001 | 0b1000101001 => {
-            //                 println!("D01.1")
-            //             }
-            //             0b1101010010 | 0b0010101101 => {
-            //                 println!("D04.4")
-            //             }
-            //             0b0011111010 | 0b1100000101 => {
-            //                 println!("K28.5 start idling...")
-            //             }
-            //             0b0011111001 | 0b1100000110 => {
-            //                 println!("K28.1 idling...")
-            //             }
-            //             0b1010101010 => {
-            //                 println!("D21.5 END idle")
-            //             }
-            //             _ => {
-            //                 println!("encoded = {:#012b}", arr[i])
-            //             }
-            //         }
-            //         last_encoded = arr[i]
-            //     }
-            // }
-            // println!("-------------------------------------");
-
             timer.delay_us(2_000_000);
         }
     }
-    fn get_encoded() -> u16 {
-        unsafe { csr::cxp::upconn_encoded_data_read().reverse_bits() >> 6 }
-    }
 }