diff --git a/CHANGELOG.rst b/CHANGELOG.rst
index bde7532..846c4d9 100644
--- a/CHANGELOG.rst
+++ b/CHANGELOG.rst
@@ -1,6 +1,11 @@
 IO Framework change log
 =======================
 
+3.5.1
+-----
+
+  * CHANGE: Updated lib_mic_array to v5.3.0
+
 3.5.0
 -----
 
diff --git a/modules/mic_array b/modules/mic_array
index 28cc9b1..e4996bd 160000
--- a/modules/mic_array
+++ b/modules/mic_array
@@ -1 +1 @@
-Subproject commit 28cc9b13ea73c9301ee6c786cb64218d773bc43e
+Subproject commit e4996bdd66d825ff7ea33e0611e748c48be20d10
diff --git a/test/build_lib_i2s_tests.sh b/test/build_lib_i2s_tests.sh
index ecc5678..de3aa19 100755
--- a/test/build_lib_i2s_tests.sh
+++ b/test/build_lib_i2s_tests.sh
@@ -9,18 +9,6 @@ source ${FRAMEWORK_IO_ROOT}/tools/ci/helper_functions.sh
 
 # row format is: "make_target BOARD toolchain"
 declare -a applications=(
-    "test_hil_backpressure_test_32_768000_4_5_5"
-    "test_hil_backpressure_test_32_768000_4_0_10"
-    "test_hil_backpressure_test_32_768000_4_10_0"
-    "test_hil_backpressure_test_32_768000_3_5_5"
-    "test_hil_backpressure_test_32_768000_3_0_10"
-    "test_hil_backpressure_test_32_768000_3_10_0"
-    "test_hil_backpressure_test_32_768000_2_5_5"
-    "test_hil_backpressure_test_32_768000_2_0_10"
-    "test_hil_backpressure_test_32_768000_2_10_0"
-    "test_hil_backpressure_test_32_768000_1_5_5"
-    "test_hil_backpressure_test_32_768000_1_0_10"
-    "test_hil_backpressure_test_32_768000_1_10_0"
     "test_hil_backpressure_test_32_384000_4_5_5"
     "test_hil_backpressure_test_32_384000_4_0_10"
     "test_hil_backpressure_test_32_384000_4_10_0"
@@ -81,18 +69,6 @@ declare -a applications=(
     "test_hil_i2s_slave_test_32_1_4_0_inv"
     "test_hil_i2s_slave_test_32_1_0_4_inv"
     "test_hil_i2s_slave_test_32_1_2_2_inv"
-    "test_hil_backpressure_test_16_768000_4_5_5"
-    "test_hil_backpressure_test_16_768000_4_0_10"
-    "test_hil_backpressure_test_16_768000_4_10_0"
-    "test_hil_backpressure_test_16_768000_3_5_5"
-    "test_hil_backpressure_test_16_768000_3_0_10"
-    "test_hil_backpressure_test_16_768000_3_10_0"
-    "test_hil_backpressure_test_16_768000_2_5_5"
-    "test_hil_backpressure_test_16_768000_2_0_10"
-    "test_hil_backpressure_test_16_768000_2_10_0"
-    "test_hil_backpressure_test_16_768000_1_5_5"
-    "test_hil_backpressure_test_16_768000_1_0_10"
-    "test_hil_backpressure_test_16_768000_1_10_0"
     "test_hil_backpressure_test_16_384000_4_5_5"
     "test_hil_backpressure_test_16_384000_4_0_10"
     "test_hil_backpressure_test_16_384000_4_10_0"
diff --git a/test/lib_i2s/backpressure_test/backpressure_test.cmake b/test/lib_i2s/backpressure_test/backpressure_test.cmake
index 554780d..4a14538 100644
--- a/test/lib_i2s/backpressure_test/backpressure_test.cmake
+++ b/test/lib_i2s/backpressure_test/backpressure_test.cmake
@@ -24,7 +24,7 @@ set(APP_LINK_OPTIONS
 # Tile Targets
 #**********************
 if(NOT DEFINED ENV{SAMPLE_RATES})
-    set(SAMPLE_RATES 768000 384000 192000)
+    set(SAMPLE_RATES 384000 192000)
 else()
     set(SAMPLE_RATES $ENV{SAMPLE_RATES})
 endif()
diff --git a/test/lib_i2s/backpressure_test/src/main.c b/test/lib_i2s/backpressure_test/src/main.c
index d28db53..0f14b9f 100644
--- a/test/lib_i2s/backpressure_test/src/main.c
+++ b/test/lib_i2s/backpressure_test/src/main.c
@@ -1,4 +1,4 @@
-// Copyright 2016-2022 XMOS LIMITED.
+// Copyright 2016-2024 XMOS LIMITED.
 // This Software is subject to the terms of the XMOS Public Licence: Version 1.
 #include <platform.h>
 #include <xs1.h>
@@ -14,7 +14,7 @@
 #define BURN_THREADS    6
 #endif
 #ifndef SAMPLE_FREQUENCY
-#define SAMPLE_FREQUENCY 768000
+#define SAMPLE_FREQUENCY 192000
 #endif
 #ifndef TEST_LEN
 #define TEST_LEN 1000
@@ -44,6 +44,127 @@
 
 #define SETSR(c) asm volatile("setsr %0" : : "n"(c));
 
+enum {
+    SAMPLE_RATE_192000,
+    SAMPLE_RATE_384000,
+    NUM_SAMPLE_RATES
+}e_sample_rates;
+
+enum {
+    BITDEPTH_16,
+    BITDEPTH_32,
+    NUM_BIT_DEPTHS
+}e_bit_depth;
+
+enum {
+    NUM_I2S_LINES_1,
+    NUM_I2S_LINES_2,
+    NUM_I2S_LINES_3,
+    NUM_I2S_LINES_4,
+}e_channel_config;
+
+static int acceptable_receive_delay = 0, acceptable_send_delay = 0;
+static int acceptable_delay_ticks[NUM_SAMPLE_RATES][NUM_I2S_LINES_4+1][NUM_BIT_DEPTHS];
+
+static inline void populate_acceptable_delay_ticks()
+{
+    // These numbers are logged by running the test and logging the delay at the last passing iteration
+    // before the backpressure test starts failing. So, on top of the bare minimum code in the i2s_send()
+    // and i2s_receive() functions in this file plus their calling overheads, we have acceptable_delay_ticks number
+    // of cycles per send and receive callback function call to add any extra processing.
+
+    // 192 KHz
+    acceptable_delay_ticks[SAMPLE_RATE_192000][NUM_I2S_LINES_1][BITDEPTH_16] = 170;
+    acceptable_delay_ticks[SAMPLE_RATE_192000][NUM_I2S_LINES_1][BITDEPTH_32] = 185;
+    acceptable_delay_ticks[SAMPLE_RATE_192000][NUM_I2S_LINES_2][BITDEPTH_16] = 140;
+    acceptable_delay_ticks[SAMPLE_RATE_192000][NUM_I2S_LINES_2][BITDEPTH_32] = 155;
+    acceptable_delay_ticks[SAMPLE_RATE_192000][NUM_I2S_LINES_3][BITDEPTH_16] = 105;
+    acceptable_delay_ticks[SAMPLE_RATE_192000][NUM_I2S_LINES_3][BITDEPTH_32] = 125;
+    acceptable_delay_ticks[SAMPLE_RATE_192000][NUM_I2S_LINES_4][BITDEPTH_16] = 70;
+    acceptable_delay_ticks[SAMPLE_RATE_192000][NUM_I2S_LINES_4][BITDEPTH_32] = 90;
+
+    // 384 KHz
+    acceptable_delay_ticks[SAMPLE_RATE_384000][NUM_I2S_LINES_1][BITDEPTH_16] = 50;
+    acceptable_delay_ticks[SAMPLE_RATE_384000][NUM_I2S_LINES_1][BITDEPTH_32] = 55;
+    acceptable_delay_ticks[SAMPLE_RATE_384000][NUM_I2S_LINES_2][BITDEPTH_16] = 15;
+    acceptable_delay_ticks[SAMPLE_RATE_384000][NUM_I2S_LINES_2][BITDEPTH_32] = 25;
+    // For 384 KHz, we have non-zero backpressure only up to 2 channels
+    acceptable_delay_ticks[SAMPLE_RATE_384000][NUM_I2S_LINES_3][BITDEPTH_16] = 0;
+    acceptable_delay_ticks[SAMPLE_RATE_384000][NUM_I2S_LINES_3][BITDEPTH_32] = 0;
+    acceptable_delay_ticks[SAMPLE_RATE_384000][NUM_I2S_LINES_4][BITDEPTH_16] = 0;
+    acceptable_delay_ticks[SAMPLE_RATE_384000][NUM_I2S_LINES_4][BITDEPTH_32] = 0;
+}
+
+void get_acceptable_delay()
+{
+    int sample_rate;
+    if(SAMPLE_FREQUENCY == 192000)
+    {
+        sample_rate = SAMPLE_RATE_192000;
+    }
+    else if(SAMPLE_FREQUENCY == 384000)
+    {
+        sample_rate = SAMPLE_RATE_384000;
+    }
+    else
+    {
+        printf("ERROR: Invalid sample rate %d\n", SAMPLE_FREQUENCY);
+        _Exit(1);
+    }
+
+    int bit_depth;
+    if(DATA_BITS == 16)
+    {
+        bit_depth = BITDEPTH_16;
+    }
+    else if(DATA_BITS == 32)
+    {
+        bit_depth = BITDEPTH_32;
+    }
+    else
+    {
+        printf("ERROR: Invalid bit_depth %d\n", DATA_BITS);
+        _Exit(1);
+    }
+    if((NUM_I2S_LINES < 1) || (NUM_I2S_LINES > 4))
+    {
+        printf("ERROR: Invalid NUM_I2S_LINES %d\n", NUM_I2S_LINES);
+        _Exit(1);
+    }
+    int delay = acceptable_delay_ticks[sample_rate][NUM_I2S_LINES-1][bit_depth];
+
+    if(delay <= 0)
+    {
+        printf("ERROR: Invalid delay %d. Check if testing an unsupported configuration\n", delay);
+        _Exit(1);
+    }
+
+    // get the send and receive delay based on the
+    if((RECEIVE_DELAY_INCREMENT == 5) && (SEND_DELAY_INCREMENT == 5))
+    {
+        // Backpressure passes at delay, so add another increment number of ticks to get to the first fail instance
+        acceptable_receive_delay = delay + 5;
+        acceptable_send_delay = delay + 5;
+    }
+    else if((RECEIVE_DELAY_INCREMENT == 0) && (SEND_DELAY_INCREMENT == 10))
+    {
+        // Backpressure passes at 2*delay, so add another increment number of ticks to get to the first fail instance
+        acceptable_receive_delay = 0;
+        acceptable_send_delay = 2*delay + 10;
+    }
+    else if((RECEIVE_DELAY_INCREMENT == 10) && (SEND_DELAY_INCREMENT == 0))
+    {
+        // Backpressure passes at 2*delay, so add another increment number of ticks to get to the first fail instance
+        acceptable_receive_delay = 2*delay + 10;
+        acceptable_send_delay = 0;
+    }
+    else
+    {
+        printf("ERROR: Unsupported receive (%d) and send (%d) delay increment combination\n", RECEIVE_DELAY_INCREMENT, SEND_DELAY_INCREMENT);
+        _Exit(1);
+    }
+}
+
 /* Ports and clocks used by the application */
 port_t p_lrclk = XS1_PORT_1G;
 port_t p_bclk = XS1_PORT_1H;
@@ -54,8 +175,9 @@ port_t p_din [4] = {XS1_PORT_1I, XS1_PORT_1J, XS1_PORT_1K, XS1_PORT_1L};
 xclock_t mclk = XS1_CLKBLK_1;
 xclock_t bclk = XS1_CLKBLK_2;
 
-static volatile int receive_delay = 5000;
+static volatile int receive_delay = 0;
 static volatile int send_delay = 0;
+static volatile int32_t receive_data_store[8];
 
 void i2s_init(void *app_data, i2s_config_t *i2s_config)
 {
@@ -75,6 +197,9 @@ void i2s_send(void *app_data, size_t n, int32_t *send_data)
 
 void i2s_receive(void *app_data, size_t n, int32_t *receive_data)
 {
+    for (size_t c = 0; c < n; c++) {
+        receive_data_store[c] = receive_data[c];
+    }
     if (receive_delay) {
         delay_ticks(receive_delay);
     }
@@ -85,11 +210,6 @@ i2s_restart_t i2s_restart_check(void *app_data)
     return I2S_NO_RESTART;
 }
 
-#if DATA_BITS == 32
-#define OVERHEAD_TICKS 185 // Some of the period needs to be allowed for the callbacks
-#else
-#define OVERHEAD_TICKS 185 // Non-32b data widths take longer to process
-#endif
 #define JITTER  1   //Allow for rounding so does not break when diff = period + 1
 #define N_CYCLES_AT_DELAY   1 //How many LR clock cycles to measure at each backpressure delay value
 #define DIFF_WRAP_16(new, old)  (new > old ? new - old : new + 0x10000 - old)
@@ -121,28 +241,40 @@ void test_lr_period() {
         port_set_trigger_in_equal(p_lr_test, 0);
         (void) port_in(p_lr_test);
         counter++;
-        if (counter == N_CYCLES_AT_DELAY) {
-            receive_delay += RECEIVE_DELAY_INCREMENT;
-            send_delay += SEND_DELAY_INCREMENT;
-            if ((receive_delay + send_delay) > (period - OVERHEAD_TICKS)) {
-                printf("PASS\n");
-                _Exit(0);
-            }
-            counter = 0;
-        }
+
         port_set_trigger_in_equal(p_lr_test, 1);
         (void) port_in(p_lr_test);
         time = port_get_trigger_time(p_lr_test);
 
         int diff = DIFF_WRAP_16(time, time_old);
         if (diff > (period + JITTER)) {
-            printf("Backpressure breaks at receive delay ticks=%d, send delay ticks=%d\n",
-            receive_delay, send_delay);
-            printf("actual diff: %d, maximum (period + Jitter): %d\n",
-            diff, (period + JITTER));
-            _Exit(1);
+            // The delay we're able to add in the i2s_receive() function should be acceptable_receive_delay ticks or more
+            if(receive_delay < acceptable_receive_delay)
+            {
+                printf("Backpressure breaks at receive delay ticks = %d, acceptable receive delay = %d\n",
+                    receive_delay, acceptable_receive_delay);
+                printf("actual diff: %d, maximum (period + Jitter): %d\n", diff, (period + JITTER));
+                _Exit(1);
+            }
+
+            // The delay we're able to add in the i2s_send() function should be acceptable_send_delay ticks or more
+            if(send_delay < acceptable_send_delay)
+            {
+                printf("Backpressure breaks at send delay ticks = %d, acceptable send delay = %d\n",
+                    send_delay, acceptable_send_delay);
+                printf("actual diff: %d, maximum (period + Jitter): %d\n", diff, (period + JITTER));
+                _Exit(1);
+            }
+            printf("PASS\n");
+            _Exit(0);
+        }
+
+        if (counter == N_CYCLES_AT_DELAY) {
+            receive_delay += RECEIVE_DELAY_INCREMENT;
+            send_delay += SEND_DELAY_INCREMENT;
+            counter = 0;
         }
-    time_old = time;
+        time_old = time;
     }
 }
 
@@ -153,6 +285,9 @@ void burn(void) {
 }
 
 int main() {
+    populate_acceptable_delay_ticks();
+    get_acceptable_delay();
+
     i2s_callback_group_t i_i2s = {
             .init = (i2s_init_t) i2s_init,
             .restart_check = (i2s_restart_check_t) i2s_restart_check,
diff --git a/test/lib_i2s/i2s_master_external_clock_test/i2s_master_external_clock_test.cmake b/test/lib_i2s/i2s_master_external_clock_test/i2s_master_external_clock_test.cmake
index 057a339..7644ab0 100644
--- a/test/lib_i2s/i2s_master_external_clock_test/i2s_master_external_clock_test.cmake
+++ b/test/lib_i2s/i2s_master_external_clock_test/i2s_master_external_clock_test.cmake
@@ -15,6 +15,8 @@ set(APP_LINK_OPTIONS
     -report
     -target=XCORE-AI-EXPLORER
 )
+# Compile main.c which contains the i2s_callback_group_t functions in O3 mode
+set_source_files_properties(${CMAKE_CURRENT_LIST_DIR}/src/main.c  PROPERTIES COMPILE_FLAGS "-O3")
 
 #**********************
 # Tile Targets
diff --git a/test/lib_i2s/i2s_master_external_clock_test/src/main.c b/test/lib_i2s/i2s_master_external_clock_test/src/main.c
index 51a26f8..03f8923 100644
--- a/test/lib_i2s/i2s_master_external_clock_test/src/main.c
+++ b/test/lib_i2s/i2s_master_external_clock_test/src/main.c
@@ -1,4 +1,4 @@
-// Copyright 2015-2022 XMOS LIMITED.
+// Copyright 2015-2024 XMOS LIMITED.
 // This Software is subject to the terms of the XMOS Public Licence: Version 1.
 #include <xs1.h>
 #include <i2s.h>
@@ -19,41 +19,49 @@ port_t setup_strobe_port = XS1_PORT_1L;
 port_t setup_data_port = XS1_PORT_16A;
 port_t  setup_resp_port = XS1_PORT_1M;
 
-#define MAX_RATIO 4
+#define MAX_RATIO 3 // 192, 96 and 48KHz
 
 #define MAX_CHANNELS 8
 
 #define MAX_NUM_RESTARTS (4)
 
-#if defined(SMOKE)
-#if NUM_OUT > 1 || NUM_IN > 1
+#ifndef DATA_BITS
+#define DATA_BITS 32
+#endif
+
+#if SMOKE
 #define NUM_MCLKS 1
+#if DATA_BITS == 32
+// Choose mclk freq such that mclk_bclk_ratio is atleast 2 for the worst case sampling freq (192KHz), since
+// mclk_bclk_ratio = 1 doesn't seem to be supported.
+static const unsigned mclock_freq[NUM_MCLKS] = {
+        24576000,
+};
+#elif DATA_BITS == 16
 static const unsigned mclock_freq[NUM_MCLKS] = {
         12288000,
 };
 #else
-#define NUM_MCLKS 1
+    #error "Invalid DATA_BITS define"
+#endif
+#else   // SMOKE = 0
+#define NUM_MCLKS 2
+#if DATA_BITS == 32
 static const unsigned mclock_freq[NUM_MCLKS] = {
         24576000,
+        22579200,
 };
-#endif
-#else
-#if NUM_OUT > 1 || NUM_IN > 1
-#define NUM_MCLKS 1
+#elif DATA_BITS == 16
 static const unsigned mclock_freq[NUM_MCLKS] = {
         12288000,
+        11289600,
 };
 #else
-#define NUM_MCLKS 1
-static const unsigned mclock_freq[NUM_MCLKS] = {
-        24576000,
-};
-#endif
+    #error "Invalid DATA_BITS define"
 #endif
-#ifndef DATA_BITS
-#define DATA_BITS 32
 #endif
 
+
 // Applications are expected to define this macro if they want non-32b I2S width
 #define I2S_DATA_BITS DATA_BITS
 
@@ -177,26 +185,42 @@ i2s_restart_t i2s_restart_check(void *app_data)
     return restart;
 }
 
-void i2s_init(void *app_data, i2s_config_t *i2s_config)
+void setup_bclock()
 {
-    //bclock frequency is not changed in restart when using i2s_frame_master_external_clock.
-    //The clock needs to be set externally once, before starting i2s_frame_master_external_clock.
+    mclk_bclk_ratio = (1 << ratio_log2);
+
+    broadcast(mclock_freq[mclock_freq_index],
+              mclk_bclk_ratio,
+              NUM_IN, NUM_OUT, DATA_BITS,
+              current_mode == I2S_MODE_I2S);
+
+    clock_enable(bclk);
+    clock_set_source_port(bclk, p_mclk);
+    clock_set_divide(bclk, mclk_bclk_ratio >> 1);
+}
 
+void i2s_init(void *app_data, i2s_config_t *i2s_config)
+{
     if (!first_time) {
         unsigned x = request_response(setup_strobe_port, setup_resp_port);
         error |= x;
         if (error) {
             printf("Error: test fail\n");
         }
-
-        if (current_mode == I2S_MODE_I2S) {
-            current_mode = I2S_MODE_LEFT_JUSTIFIED;
+        if (ratio_log2 == MAX_RATIO) {
+            ratio_log2 = 1;
+            if (mclock_freq_index == NUM_MCLKS - 1) {
+                mclock_freq_index = 0;
+                if (current_mode == I2S_MODE_I2S) {
+                    current_mode = I2S_MODE_LEFT_JUSTIFIED;
+                } else {
+                    _Exit(1);
+                }
+            } else {
+                mclock_freq_index++;
+            }
         } else {
-            current_mode = I2S_MODE_I2S;
-        }
-
-        if (num_restarts >= MAX_NUM_RESTARTS) {
-            _Exit(1);
+            ratio_log2++;
         }
     }
 
@@ -211,27 +235,7 @@ void i2s_init(void *app_data, i2s_config_t *i2s_config)
         rx_data_counter[i] = 0;
     }
 
-    broadcast(mclock_freq[mclock_freq_index],
-              mclk_bclk_ratio,
-              NUM_IN, NUM_OUT, DATA_BITS,
-              i2s_config->mode == I2S_MODE_I2S);
-}
-
-void setup_bclock()
-{
-    mclock_freq_index = 0;
-    ratio_log2 = 1;
-    mclk_bclk_ratio = (1 << ratio_log2);
-    current_mode = I2S_MODE_I2S;
-
-    broadcast(mclock_freq[mclock_freq_index],
-              mclk_bclk_ratio,
-              NUM_IN, NUM_OUT, DATA_BITS,
-              current_mode == I2S_MODE_I2S);
-
-    clock_enable(bclk);
-    clock_set_source_port(bclk, p_mclk);
-    clock_set_divide(bclk, mclk_bclk_ratio >> 1);
+    setup_bclock();
 }
 
 DECLARE_JOB(spin, (void));
@@ -256,8 +260,6 @@ int main(){
     port_enable(p_mclk);
     port_enable(p_bclk);
 
-    setup_bclock();
-
     PAR_JOBS (
         PJOB(i2s_master_external_clock, (
             &i_i2s,
diff --git a/test/lib_i2s/i2s_master_test/i2s_master_test.cmake b/test/lib_i2s/i2s_master_test/i2s_master_test.cmake
index ece0872..1f70361 100644
--- a/test/lib_i2s/i2s_master_test/i2s_master_test.cmake
+++ b/test/lib_i2s/i2s_master_test/i2s_master_test.cmake
@@ -16,6 +16,9 @@ set(APP_LINK_OPTIONS
     -target=XCORE-AI-EXPLORER
 )
 
+# Compile main.c which contains the i2s_callback_group_t functions in O3 mode
+set_source_files_properties(${CMAKE_CURRENT_LIST_DIR}/src/main.c  PROPERTIES COMPILE_FLAGS "-O3")
+
 #**********************
 # Tile Targets
 #**********************
diff --git a/test/lib_i2s/i2s_master_test/src/main.c b/test/lib_i2s/i2s_master_test/src/main.c
index 6c032bf..2e1698e 100644
--- a/test/lib_i2s/i2s_master_test/src/main.c
+++ b/test/lib_i2s/i2s_master_test/src/main.c
@@ -1,4 +1,4 @@
-// Copyright 2015-2022 XMOS LIMITED.
+// Copyright 2015-2024 XMOS LIMITED.
 // This Software is subject to the terms of the XMOS Public Licence: Version 1.
 #include <xs1.h>
 #include <i2s.h>
@@ -19,42 +19,46 @@ port_t setup_strobe_port = XS1_PORT_1L;
 port_t setup_data_port = XS1_PORT_16A;
 port_t setup_resp_port = XS1_PORT_1M;
 
-#define MAX_RATIO 4
+#define MAX_RATIO 3 // 192, 96 and 48KHz
 
 #define MAX_CHANNELS 8
 
-#if defined(SMOKE)
-#if NUM_OUT > 1 || NUM_IN > 1
-#define NUM_MCLKS 1
-static const unsigned mclock_freq[NUM_MCLKS] = {
-        12288000,
-};
-#else
+#ifndef DATA_BITS
+#define DATA_BITS 32
+#endif
+
+#if SMOKE
 #define NUM_MCLKS 1
+#if DATA_BITS == 32
+// Choose mclk freq such that mclk_bclk_ratio is atleast 2 for the worst case sampling freq (192KHz), since
+// mclk_bclk_ratio = 1 doesn't seem to be supported.
 static const unsigned mclock_freq[NUM_MCLKS] = {
         24576000,
 };
-#endif
-#else
-#if NUM_OUT > 1 || NUM_IN > 1
-#define NUM_MCLKS 2
+#elif DATA_BITS == 16
 static const unsigned mclock_freq[NUM_MCLKS] = {
         12288000,
-        11289600,
 };
 #else
-#define NUM_MCLKS 4
+    #error "Invalid DATA_BITS define"
+#endif
+#else   // SMOKE = 0
+#define NUM_MCLKS 2
+#if DATA_BITS == 32
 static const unsigned mclock_freq[NUM_MCLKS] = {
         24576000,
         22579200,
+};
+#elif DATA_BITS == 16
+static const unsigned mclock_freq[NUM_MCLKS] = {
         12288000,
         11289600,
 };
+#else
+    #error "Invalid DATA_BITS define"
 #endif
 #endif
-#ifndef DATA_BITS
-#define DATA_BITS 32
-#endif
+
 
 // Applications are expected to define this macro if they want non-32b I2S width
 #define I2S_DATA_BITS DATA_BITS
@@ -173,17 +177,6 @@ i2s_restart_t i2s_restart_check(void *app_data)
 
 void i2s_init(void *app_data, i2s_config_t *i2s_config)
 {
-    /*
-     * We're going to manually disable the 16b 192 kHz 8i8o test as it does not
-     * pass in this implementation (but does in lib_i2s!). This is the first
-     * thing tested in this sequence, so must first advance ratio_log2
-     * by one to start with.
-     */
-    if (DATA_BITS == 16 && NUM_IN == 4 && NUM_OUT == 4 && first_time)
-    {
-        ratio_log2++;
-    }
-
     if (!first_time) {
         unsigned x = request_response(setup_strobe_port, setup_resp_port);
         error |= x;
@@ -191,36 +184,20 @@ void i2s_init(void *app_data, i2s_config_t *i2s_config)
             printf("Error: test fail\n");
         }
 
-        int s = 0;
-        while (!s) {
-            if (ratio_log2 == MAX_RATIO) {
-                ratio_log2 = 1;
-                if (mclock_freq_index == NUM_MCLKS - 1) {
-                    mclock_freq_index = 0;
-                    if (current_mode == I2S_MODE_I2S) {
-                        current_mode = I2S_MODE_LEFT_JUSTIFIED;
-                    } else {
-                        _Exit(1);
-                    }
+        if (ratio_log2 == MAX_RATIO) {
+            ratio_log2 = 1;
+            if (mclock_freq_index == NUM_MCLKS - 1) {
+                mclock_freq_index = 0;
+                if (current_mode == I2S_MODE_I2S) {
+                    current_mode = I2S_MODE_LEFT_JUSTIFIED;
                 } else {
-                    mclock_freq_index++;
+                    _Exit(1);
                 }
             } else {
-                ratio_log2++;
-            }
-            
-            uint32_t new_sample_rate = mclock_freq[mclock_freq_index] / ((1 << ratio_log2) * (2 * DATA_BITS));
-
-            if (new_sample_rate >= 48000)
-            {
-                s = 1;
-            }
-
-            // And then we need to skip the second time it comes up in testing
-            if (new_sample_rate == 192000 && DATA_BITS == 16 && NUM_IN == 4 && NUM_OUT == 4)
-            {
-                s = 0;
+                mclock_freq_index++;
             }
+        } else {
+            ratio_log2++;
         }
     }
 
diff --git a/test/lib_i2s/i2s_slave_checker.py b/test/lib_i2s/i2s_slave_checker.py
index 7369977..0a48ce1 100644
--- a/test/lib_i2s/i2s_slave_checker.py
+++ b/test/lib_i2s/i2s_slave_checker.py
@@ -92,7 +92,7 @@ def run(self):
                 xsi, self._setup_strobe_port, self._setup_data_port
             )
             xsi.drive_port_pins(self._bclk, bclk1)
-            xsi.drive_port_pins(self._lrclk, 1)
+            xsi.drive_port_pins(self._lrclk, 0)
 
             bclk_frequency = (bclk_frequency_u << 16) + bclk_frequency_l
             print(
@@ -146,6 +146,10 @@ def run(self):
             #       the range 32 - 63, lr_clock outputs 1, else it outputs 0.
             time = float(xsi.get_time())
 
+            time = self.wait_until_ret(
+                time + (clock_half_period * 64)
+            )  # Add extra delay to ensure that the i2s_slave device sees the LRCLK transitions in the first for loop below
+
             lr_counter = data_bits + (data_bits // 2) + (is_i2s_justified)
             lr_count_max = (2 * data_bits) - 1
 
@@ -213,7 +217,7 @@ def run(self):
                         time = self.wait_until_ret(
                             time + clock_half_period - din_sample_offset
                         )
-            
+
                 data_bit_mask = int("1" * data_bits, base=2)
 
                 for p in range(0, num_outs):
diff --git a/test/lib_i2s/i2s_slave_test/i2s_slave_test.cmake b/test/lib_i2s/i2s_slave_test/i2s_slave_test.cmake
index 274af37..a7b1539 100644
--- a/test/lib_i2s/i2s_slave_test/i2s_slave_test.cmake
+++ b/test/lib_i2s/i2s_slave_test/i2s_slave_test.cmake
@@ -16,6 +16,10 @@ set(APP_LINK_OPTIONS
     -target=XCORE-AI-EXPLORER
 )
 
+# Compile main.c which contains the i2s_callback_group_t functions in O3 mode. Needed for passing the
+# test_i2s_basic_slave[4ch_in,4ch_out-32b] and test_i2s_basic_slave[4ch_in,4ch_out-16b] tests
+set_source_files_properties(${CMAKE_CURRENT_LIST_DIR}/src/main.c  PROPERTIES COMPILE_FLAGS "-O3")
+
 #**********************
 # Tile Targets
 #**********************
diff --git a/test/lib_i2s/i2s_slave_test/src/main.c b/test/lib_i2s/i2s_slave_test/src/main.c
index 7fe32c0..fd520fd 100644
--- a/test/lib_i2s/i2s_slave_test/src/main.c
+++ b/test/lib_i2s/i2s_slave_test/src/main.c
@@ -1,4 +1,4 @@
-// Copyright 2015-2022 XMOS LIMITED.
+// Copyright 2015-2024 XMOS LIMITED.
 // This Software is subject to the terms of the XMOS Public Licence: Version 1.
 #include <xs1.h>
 #include <i2s.h>
@@ -23,17 +23,14 @@ xclock_t bclk = XS1_CLKBLK_1;
 #define I2S_LOOPBACK_LATENCY 1
 
 #if SMOKE == 1
-#define NUM_BCLKS 1
-#define NUM_BCLKS_TO_CHECK 1
-static const unsigned bclk_freq_lut[NUM_BCLKS] = {
-  1228800
+#define NUM_LRCLKS_TO_CHECK 1
+static const unsigned lr_freq_lut[] = {
+  192000
 };
 #else
-#define NUM_BCLKS 12
-#define NUM_BCLKS_TO_CHECK 3
-static const unsigned bclk_freq_lut[NUM_BCLKS] = {
-  1228800, 614400, 384000, 192000, 44100,
-  22050, 96000, 176400, 88200, 48000, 24000, 352800
+#define NUM_LRCLKS_TO_CHECK 6
+static const unsigned lr_freq_lut[] = {
+  192000, 176400, 96000, 88200, 48000, 44100
 };
 #endif
 #ifndef DATA_BITS
@@ -111,7 +108,7 @@ static int request_response(
     return r;
 }
 
-static unsigned bclk_freq_index = 0;
+static unsigned lr_freq_index = 0;
 static unsigned frames_sent = 0;
 static unsigned rx_data_counter[MAX_CHANNELS] = {0};
 static unsigned tx_data_counter[MAX_CHANNELS] = {0};
@@ -150,11 +147,12 @@ i2s_restart_t i2s_restart_check(void *app_data)
     i2s_restart_t restart;
 
     frames_sent++;
-    if (frames_sent == 4)
+    if (frames_sent == 4) {
       restart = I2S_RESTART;
-    else
+    }
+    else {
       restart = I2S_NO_RESTART;
-
+    }
     return restart;
 }
 
@@ -173,15 +171,15 @@ void i2s_init(void *app_data, i2s_config_t *i2s_config)
             printf("Error\n");
         }
 
-        if (bclk_freq_index == NUM_BCLKS_TO_CHECK - 1) {
+        if (lr_freq_index == NUM_LRCLKS_TO_CHECK - 1) {
             if (current_mode == I2S_MODE_I2S) {
                 current_mode = I2S_MODE_LEFT_JUSTIFIED;
-                bclk_freq_index = 0;
+                lr_freq_index = 0;
             } else {
                 _Exit(1);
             }
         } else {
-            bclk_freq_index++;
+            lr_freq_index++;
         }
     }
 
@@ -196,7 +194,9 @@ void i2s_init(void *app_data, i2s_config_t *i2s_config)
         rx_data_counter[i] = 0;
     }
 
-    broadcast(bclk_freq_lut[bclk_freq_index],
+    unsigned bclk_freq = lr_freq_lut[lr_freq_index] * DATA_BITS * I2S_CHANS_PER_FRAME;
+
+    broadcast(bclk_freq,
               NUM_IN,
               NUM_OUT, DATA_BITS, i2s_config->mode == I2S_MODE_I2S);
 
diff --git a/test/lib_i2s/test_backpressure.py b/test/lib_i2s/test_backpressure.py
index 020da02..e31ceab 100644
--- a/test/lib_i2s/test_backpressure.py
+++ b/test/lib_i2s/test_backpressure.py
@@ -5,7 +5,7 @@
 import subprocess
 from pathlib import Path
 
-sample_rate_args = {"768kbps": 768000, "384kbps": 384000, "192kbps": 192000}
+sample_rate_args = {"384kbps": 384000, "192kbps": 192000}
 
 num_channels_args = {"1ch": 1, "2ch": 2, "3ch": 3, "4ch": 4}
 
@@ -17,7 +17,12 @@
 
 bitdepth_args = {"16b": 16, "32b": 32}
 
+# 384000 has a non-zero backpressure only upto 2 channels
+def uncollect_if(bitdepth, sample_rate, num_channels, receive_increment, send_increment):
+    if sample_rate == 384000 and num_channels > 2:
+        return True
 
+@pytest.mark.uncollect_if(func=uncollect_if)
 @pytest.mark.parametrize("bitdepth", bitdepth_args.values(), ids=bitdepth_args.keys())
 @pytest.mark.parametrize(
     "sample_rate", sample_rate_args.values(), ids=sample_rate_args.keys()
@@ -41,9 +46,6 @@ def test_i2s_backpressure(
     send_increment,
     bitdepth,
 ):
-    if (num_channels != 4) and not nightly:
-        pytest.skip("Only run 4 channel tests unless it is a nightly")
-
     id_string = (
         f"{bitdepth}_{sample_rate}_{num_channels}_{receive_increment}_{send_increment}"
     )
diff --git a/test/lib_i2s/test_basic_master_external_clock.py b/test/lib_i2s/test_basic_master_external_clock.py
index 8d779a2..a7ef151 100644
--- a/test/lib_i2s/test_basic_master_external_clock.py
+++ b/test/lib_i2s/test_basic_master_external_clock.py
@@ -16,12 +16,6 @@
 
 bitdepth_args = {"16b": 16, "32b": 32}
 
-# 16b 4i4o (8ch in/8ch out) currently does not pass
-def uncollect_if(bitdepth, num_in, num_out):
-    if bitdepth == 16 and num_in == 4 and num_out == 4:
-        return True
-
-@pytest.mark.uncollect_if(func=uncollect_if)
 @pytest.mark.parametrize("bitdepth", bitdepth_args.values(), ids=bitdepth_args.keys())
 @pytest.mark.parametrize(
     ("num_in", "num_out"), num_in_out_args.values(), ids=num_in_out_args.keys()
diff --git a/test/lib_i2s/test_i2s_basic_master.py b/test/lib_i2s/test_i2s_basic_master.py
index 6861b40..51ab1f0 100644
--- a/test/lib_i2s/test_i2s_basic_master.py
+++ b/test/lib_i2s/test_i2s_basic_master.py
@@ -76,7 +76,7 @@ def test_i2s_basic_master(build, capfd, nightly, request, bitdepth, num_in, num_
                 simthreads=[clk, checker],
                 simargs=[
                     "--vcd-tracing",
-                    f"-o i2s_trace_{num_in}_{num_out}.vcd -tile tile[0] -cycles -ports -ports-detailed -cores -instructions",
+                    f"-o i2s_trace_{num_in}_{num_out}.vcd -tile tile[0] -cycles -ports -ports-detailed -cores -instructions -clock-blocks",
                     "--trace-to",
                     f"i2s_trace_{num_in}_{num_out}.txt",
                 ],
diff --git a/test/lib_i2s/test_i2s_basic_slave.py b/test/lib_i2s/test_i2s_basic_slave.py
index 3ba6bb6..2ea7bd4 100644
--- a/test/lib_i2s/test_i2s_basic_slave.py
+++ b/test/lib_i2s/test_i2s_basic_slave.py
@@ -10,6 +10,7 @@
 
 num_in_out_args = {
     "4ch_in,4ch_out": (4, 4),
+    "2ch_in,2ch_out": (2, 2),
     "1ch_in,1ch_out": (1, 1),
     "4ch_in,0ch_out": (4, 0),
     "0ch_in,4ch_out": (0, 4),
diff --git a/test/lib_i2s/test_slave_bclk_invert.py b/test/lib_i2s/test_slave_bclk_invert.py
index 27c03a4..8948056 100644
--- a/test/lib_i2s/test_slave_bclk_invert.py
+++ b/test/lib_i2s/test_slave_bclk_invert.py
@@ -6,7 +6,13 @@
 import pytest
 import Pyxsim as px
 
-num_in_out_args = {"2ch_in,2ch_out": (2, 2)}
+num_in_out_args = {
+    "4ch_in,4ch_out": (4, 4),
+    "2ch_in,2ch_out": (2, 2),
+    "1ch_in,1ch_out": (1, 1),
+    "4ch_in,0ch_out": (4, 0),
+    "0ch_in,4ch_out": (0, 4),
+}
 
 bitdepth_args = {"16b": 16, "32b": 32}