diff --git a/keyboards/massdrop/alt/matrix.c b/keyboards/massdrop/alt/matrix.c
index 892d38791..472479d30 100644
--- a/keyboards/massdrop/alt/matrix.c
+++ b/keyboards/massdrop/alt/matrix.c
@@ -79,8 +79,6 @@ void matrix_init(void)
     matrix_init_quantum();
 }
 
-#define MATRIX_SCAN_DELAY 10   //Delay after setting a col to output (in us)
-
 uint64_t mdebouncing = 0;
 uint8_t matrix_scan(void)
 {
@@ -89,9 +87,7 @@ uint8_t matrix_scan(void)
     uint8_t col;
     uint32_t scans[2]; //PA PB
 
-    if (CLK_get_ms() < mdebouncing) return 1; //mdebouncing == 0 when no debouncing active
-
-    //DBG_1_OFF; //Profiling scans
+    if (timer_read64() < mdebouncing) return 1; //mdebouncing == 0 when no debouncing active
 
     memset(mlatest, 0, MATRIX_ROWS * sizeof(matrix_row_t)); //Zero the result buffer
 
@@ -99,7 +95,7 @@ uint8_t matrix_scan(void)
     {
         PORT->Group[col_ports[col]].OUTSET.reg = 1 << col_pins[col]; //Set col output
 
-        CLK_delay_us(MATRIX_SCAN_DELAY); //Delay for output
+        wait_us(1); //Delay for output
 
         scans[PA] = PORT->Group[PA].IN.reg & row_masks[PA]; //Read PA row pins data
         scans[PB] = PORT->Group[PB].IN.reg & row_masks[PB]; //Read PB row pins data
@@ -132,11 +128,9 @@ uint8_t matrix_scan(void)
     else
     {
         //Begin or extend debounce on change
-        mdebouncing = CLK_get_ms() + DEBOUNCING_DELAY;
+        mdebouncing = timer_read64() + DEBOUNCING_DELAY;
     }
 
-    //DBG_1_ON; //Profiling scans
-
     matrix_scan_quantum();
 
     return 1;
diff --git a/keyboards/massdrop/ctrl/matrix.c b/keyboards/massdrop/ctrl/matrix.c
index 3580577dc..5f1741e58 100644
--- a/keyboards/massdrop/ctrl/matrix.c
+++ b/keyboards/massdrop/ctrl/matrix.c
@@ -79,8 +79,6 @@ void matrix_init(void)
     matrix_init_quantum();
 }
 
-#define MATRIX_SCAN_DELAY 10   //Delay after setting a col to output (in us)
-
 uint64_t mdebouncing = 0;
 uint8_t matrix_scan(void)
 {
@@ -89,9 +87,7 @@ uint8_t matrix_scan(void)
     uint8_t col;
     uint32_t scans[2]; //PA PB
 
-    if (CLK_get_ms() < mdebouncing) return 1; //mdebouncing == 0 when no debouncing active
-
-    //DBG_1_OFF; //Profiling scans
+    if (timer_read64() < mdebouncing) return 1; //mdebouncing == 0 when no debouncing active
 
     memset(mlatest, 0, MATRIX_ROWS * sizeof(matrix_row_t)); //Zero the result buffer
 
@@ -99,7 +95,7 @@ uint8_t matrix_scan(void)
     {
         PORT->Group[col_ports[col]].OUTSET.reg = 1 << col_pins[col]; //Set col output
 
-        CLK_delay_us(MATRIX_SCAN_DELAY); //Delay for output
+        wait_us(1); //Delay for output
 
         scans[PA] = PORT->Group[PA].IN.reg & row_masks[PA]; //Read PA row pins data
         scans[PB] = PORT->Group[PB].IN.reg & row_masks[PB]; //Read PB row pins data
@@ -132,11 +128,9 @@ uint8_t matrix_scan(void)
     else
     {
         //Begin or extend debounce on change
-        mdebouncing = CLK_get_ms() + DEBOUNCING_DELAY;
+        mdebouncing = timer_read64() + DEBOUNCING_DELAY;
     }
 
-    //DBG_1_ON; //Profiling scans
-
     matrix_scan_quantum();
 
     return 1;
diff --git a/tmk_core/common/arm_atsam/timer.c b/tmk_core/common/arm_atsam/timer.c
index bcfe5002c..6c3905e30 100644
--- a/tmk_core/common/arm_atsam/timer.c
+++ b/tmk_core/common/arm_atsam/timer.c
@@ -9,7 +9,7 @@ void set_time(uint64_t tset)
 
 void timer_init(void)
 {
-    ms_clk = 0;
+    timer_clear();
 }
 
 uint16_t timer_read(void)
@@ -37,23 +37,7 @@ uint32_t timer_elapsed32(uint32_t tlast)
     return TIMER_DIFF_32(timer_read32(), tlast);
 }
 
-uint32_t timer_elapsed64(uint32_t tlast)
-{
-    uint64_t tnow = timer_read64();
-    return (tnow >= tlast ? tnow - tlast : UINT64_MAX - tlast + tnow);
-}
-
 void timer_clear(void)
 {
-    ms_clk = 0;
-}
-
-void wait_ms(uint64_t msec)
-{
-    CLK_delay_ms(msec);
-}
-
-void wait_us(uint16_t usec)
-{
-    CLK_delay_us(usec);
+    set_time(0);
 }
diff --git a/tmk_core/common/wait.h b/tmk_core/common/wait.h
index a7cded942..a77840bce 100644
--- a/tmk_core/common/wait.h
+++ b/tmk_core/common/wait.h
@@ -15,6 +15,10 @@ extern "C" {
 #   include "ch.h"
 #   define wait_ms(ms) chThdSleepMilliseconds(ms)
 #   define wait_us(us) chThdSleepMicroseconds(us)
+#elif defined PROTOCOL_ARM_ATSAM
+#   include "clks.h"
+#   define wait_ms(ms) CLK_delay_ms(ms)
+#   define wait_us(us) CLK_delay_us(us)
 #elif defined(__arm__)
 #   include "wait_api.h"
 #else  // Unit tests
diff --git a/tmk_core/protocol/arm_atsam/arm_atsam_protocol.h b/tmk_core/protocol/arm_atsam/arm_atsam_protocol.h
index 2ba099174..928af8c7e 100644
--- a/tmk_core/protocol/arm_atsam/arm_atsam_protocol.h
+++ b/tmk_core/protocol/arm_atsam/arm_atsam_protocol.h
@@ -21,8 +21,10 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #include "samd51j18a.h"
 #include "md_bootloader.h"
 
+#include "timer.h"
 #include "d51_util.h"
 #include "clks.h"
+#include "wait.h"
 #include "adc.h"
 #include "i2c_master.h"
 #include "spi.h"
diff --git a/tmk_core/protocol/arm_atsam/clks.c b/tmk_core/protocol/arm_atsam/clks.c
index 8768d0a99..1ff318e59 100644
--- a/tmk_core/protocol/arm_atsam/clks.c
+++ b/tmk_core/protocol/arm_atsam/clks.c
@@ -21,8 +21,8 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 volatile clk_t system_clks;
 volatile uint64_t ms_clk;
-
-volatile uint8_t us_delay_done;
+uint32_t usec_delay_mult;
+#define USEC_DELAY_LOOP_CYCLES 3 //Sum of instruction cycles in us delay loop
 
 const uint32_t sercom_apbbase[] = {(uint32_t)SERCOM0,(uint32_t)SERCOM1,(uint32_t)SERCOM2,(uint32_t)SERCOM3,(uint32_t)SERCOM4,(uint32_t)SERCOM5};
 const uint8_t sercom_pchan[] = {7, 8, 23, 24, 34, 35};
@@ -73,6 +73,9 @@ void CLK_oscctrl_init(void)
 
     system_clks.freq_gclk[0] = system_clks.freq_dpll[0];
 
+    usec_delay_mult = system_clks.freq_gclk[0] / (USEC_DELAY_LOOP_CYCLES * 1000000);
+    if (usec_delay_mult < 1) usec_delay_mult = 1; //Never allow a multiplier of zero
+
     DBGC(DC_CLK_OSC_INIT_COMPLETE);
 }
 
@@ -158,23 +161,11 @@ void TC4_Handler()
     }
 }
 
-void TC5_Handler()
-{
-    if (TC5->COUNT16.INTFLAG.bit.MC0)
-    {
-        TC5->COUNT16.INTFLAG.reg = TC_INTENCLR_MC0;
-        us_delay_done = 1;
-        TC5->COUNT16.CTRLA.bit.ENABLE = 0;
-        while (TC5->COUNT16.SYNCBUSY.bit.ENABLE) {}
-    }
-}
-
 uint32_t CLK_enable_timebase(void)
 {
     Gclk *pgclk = GCLK;
     Mclk *pmclk = MCLK;
     Tc *ptc4 = TC4;
-    Tc *ptc5 = TC5;
     Tc *ptc0 = TC0;
     Evsys *pevsys = EVSYS;
 
@@ -189,11 +180,6 @@ uint32_t CLK_enable_timebase(void)
     pgclk->PCHCTRL[TC4_GCLK_ID].bit.GEN = GEN_TC45;
     pgclk->PCHCTRL[TC4_GCLK_ID].bit.CHEN = 1;
 
-    //unmask TC5 sourcegclk2 to TC5
-    pmclk->APBCMASK.bit.TC5_ = 1;
-    pgclk->PCHCTRL[TC5_GCLK_ID].bit.GEN = GEN_TC45;
-    pgclk->PCHCTRL[TC5_GCLK_ID].bit.CHEN = 1;
-
     //configure TC4
     DBGC(DC_CLK_ENABLE_TIMEBASE_TC4_BEGIN);
     ptc4->COUNT16.CTRLA.bit.ENABLE = 0;
@@ -220,30 +206,6 @@ uint32_t CLK_enable_timebase(void)
 
     DBGC(DC_CLK_ENABLE_TIMEBASE_TC4_COMPLETE);
 
-    //configure TC5
-    DBGC(DC_CLK_ENABLE_TIMEBASE_TC5_BEGIN);
-    ptc5->COUNT16.CTRLA.bit.ENABLE = 0;
-    while (ptc5->COUNT16.SYNCBUSY.bit.ENABLE) { DBGC(DC_CLK_ENABLE_TIMEBASE_TC5_SYNC_DISABLE); }
-    ptc5->COUNT16.CTRLA.bit.SWRST = 1;
-    while (ptc5->COUNT16.SYNCBUSY.bit.SWRST) { DBGC(DC_CLK_ENABLE_TIMEBASE_TC5_SYNC_SWRST_1); }
-    while (ptc5->COUNT16.CTRLA.bit.SWRST) { DBGC(DC_CLK_ENABLE_TIMEBASE_TC5_SYNC_SWRST_2); }
-
-    //CTRLA defaults
-    //CTRLB as default, counting up
-    ptc5->COUNT16.CTRLBCLR.reg = 5;
-    while (ptc5->COUNT16.SYNCBUSY.bit.CTRLB) { DBGC(DC_CLK_ENABLE_TIMEBASE_TC5_SYNC_CLTRB); }
-    //ptc5->COUNT16.DBGCTRL.bit.DBGRUN = 1;
-
-    //wave mode
-    ptc5->COUNT16.WAVE.bit.WAVEGEN = 1; //MFRQ match frequency mode, toggle each CC match
-    //generate event for next stage
-    ptc5->COUNT16.EVCTRL.bit.MCEO0 = 1;
-
-    NVIC_EnableIRQ(TC5_IRQn);
-    ptc5->COUNT16.INTENSET.bit.MC0 = 1;
-
-    DBGC(DC_CLK_ENABLE_TIMEBASE_TC5_COMPLETE);
-
     //unmask TC0,1, sourcegclk2 to TC0,1
     pmclk->APBAMASK.bit.TC0_ = 1;
     pgclk->PCHCTRL[TC0_GCLK_ID].bit.GEN = GEN_TC45;
@@ -289,37 +251,27 @@ uint32_t CLK_enable_timebase(void)
     return 0;
 }
 
-uint32_t CLK_get_ms(void)
+void CLK_delay_us(uint32_t usec)
 {
-    return ms_clk;
-}
-
-void CLK_delay_us(uint16_t usec)
-{
-    us_delay_done = 0;
-
-    if (TC5->COUNT16.CTRLA.bit.ENABLE)
-    {
-        TC5->COUNT16.CTRLA.bit.ENABLE = 0;
-        while (TC5->COUNT16.SYNCBUSY.bit.ENABLE) {}
-    }
-
-    if (usec < 10) usec = 0;
-    else usec -= 10;
-
-    TC5->COUNT16.CC[0].reg = usec;
-    while (TC5->COUNT16.SYNCBUSY.bit.CC0) {}
-
-    TC5->COUNT16.CTRLA.bit.ENABLE = 1;
-    while (TC5->COUNT16.SYNCBUSY.bit.ENABLE) {}
-
-    while (!us_delay_done) {}
+    asm (
+        "CBZ R0, return\n\t"        //If usec == 0, branch to return label
+    );
+    asm (
+        "MULS R0, %0\n\t"           //Multiply R0(usec) by usec_delay_mult and store in R0
+        ".balign 16\n\t"            //Ensure loop is aligned for fastest performance
+        "loop: SUBS R0, #1\n\t"     //Subtract 1 from R0 and update flags (1 cycle)
+        "BNE loop\n\t"              //Branch if non-zero to loop label (2 cycles)  NOTE: USEC_DELAY_LOOP_CYCLES is the sum of loop cycles
+        "return:\n\t"               //Return label
+        : //No output registers
+        : "r" (usec_delay_mult)     //For %0
+    );
+    //Note: BX LR generated
 }
 
 void CLK_delay_ms(uint64_t msec)
 {
-    msec += CLK_get_ms();
-    while (msec > CLK_get_ms()) {}
+    msec += timer_read64();
+    while (msec > timer_read64()) {}
 }
 
 void clk_enable_sercom_apbmask(int sercomn)
diff --git a/tmk_core/protocol/arm_atsam/clks.h b/tmk_core/protocol/arm_atsam/clks.h
index 96819bfdd..1b01a1764 100644
--- a/tmk_core/protocol/arm_atsam/clks.h
+++ b/tmk_core/protocol/arm_atsam/clks.h
@@ -77,9 +77,8 @@ void CLK_oscctrl_init(void);
 void CLK_reset_time(void);
 uint32_t CLK_set_gclk_freq(uint8_t gclkn, uint32_t freq);
 uint32_t CLK_enable_timebase(void);
-uint32_t CLK_get_ms(void);
-uint64_t CLK_get_us(void);
-void CLK_delay_us(uint16_t usec);
+uint64_t timer_read64(void);
+void CLK_delay_us(uint32_t usec);
 void CLK_delay_ms(uint64_t msec);
 
 uint32_t CLK_set_spi_freq(uint8_t sercomn, uint32_t freq);
diff --git a/tmk_core/protocol/arm_atsam/i2c_master.c b/tmk_core/protocol/arm_atsam/i2c_master.c
index f608a79cc..d91a851f3 100644
--- a/tmk_core/protocol/arm_atsam/i2c_master.c
+++ b/tmk_core/protocol/arm_atsam/i2c_master.c
@@ -265,12 +265,12 @@ uint8_t I2C3733_Init_Control(void)
     //USB state machine will enable driver when communication is ready
     I2C3733_Control_Set(0);
 
-    CLK_delay_ms(1);
+    wait_ms(1);
 
     sr_exp_data.bit.IRST = 0;
     SR_EXP_WriteData();
 
-    CLK_delay_ms(1);
+    wait_ms(1);
 
     DBGC(DC_I2C3733_INIT_CONTROL_COMPLETE);
 
diff --git a/tmk_core/protocol/arm_atsam/led_matrix.c b/tmk_core/protocol/arm_atsam/led_matrix.c
index e914fc80e..9ef7393a2 100644
--- a/tmk_core/protocol/arm_atsam/led_matrix.c
+++ b/tmk_core/protocol/arm_atsam/led_matrix.c
@@ -494,11 +494,11 @@ void led_matrix_task(void)
     if (led_enabled)
     {
         //If an update may run and frame processing has completed
-        if (CLK_get_ms() >= led_next_run && led_cur == lede)
+        if (timer_read64() >= led_next_run && led_cur == lede)
         {
             uint8_t drvid;
 
-            led_next_run = CLK_get_ms() + LED_UPDATE_RATE;  //Set next frame update time
+            led_next_run = timer_read64() + LED_UPDATE_RATE;  //Set next frame update time
 
             //NOTE: GCR does not need to be timed with LED processing, but there is really no harm
             if (gcr_actual != gcr_actual_last)
diff --git a/tmk_core/protocol/arm_atsam/main_arm_atsam.c b/tmk_core/protocol/arm_atsam/main_arm_atsam.c
index 2bda7d7c7..eaad66e9f 100644
--- a/tmk_core/protocol/arm_atsam/main_arm_atsam.c
+++ b/tmk_core/protocol/arm_atsam/main_arm_atsam.c
@@ -159,7 +159,7 @@ void send_consumer(uint16_t data)
 
 void main_subtask_usb_state(void)
 {
-    static uint32_t fsmstate_on_delay = 0;                          //Delay timer to be sure USB is actually operating before bringing up hardware
+    static uint64_t fsmstate_on_delay = 0;                          //Delay timer to be sure USB is actually operating before bringing up hardware
     uint8_t fsmstate_now = USB->DEVICE.FSMSTATUS.reg;               //Current state from hardware register
 
     if (fsmstate_now == USB_FSMSTATUS_FSMSTATE_SUSPEND_Val)         //If USB SUSPENDED
@@ -188,9 +188,9 @@ void main_subtask_usb_state(void)
         {
             if (fsmstate_on_delay == 0)                             //If ON delay timer is cleared
             {
-                fsmstate_on_delay = CLK_get_ms() + 250;             //Set ON delay timer
+                fsmstate_on_delay = timer_read64() + 250;             //Set ON delay timer
             }
-            else if (CLK_get_ms() > fsmstate_on_delay)              //Else if ON delay timer is active and timed out
+            else if (timer_read64() > fsmstate_on_delay)              //Else if ON delay timer is active and timed out
             {
                 suspend_wakeup_init();                              //Run wakeup routine
                 g_usb_state = fsmstate_now;                         //Save current USB state
@@ -214,9 +214,9 @@ void main_subtask_power_check(void)
 {
     static uint64_t next_5v_checkup = 0;
 
-    if (CLK_get_ms() > next_5v_checkup)
+    if (timer_read64() > next_5v_checkup)
     {
-        next_5v_checkup = CLK_get_ms() + 5;
+        next_5v_checkup = timer_read64() + 5;
 
         v_5v = adc_get(ADC_5V);
         v_5v_avg = 0.9 * v_5v_avg + 0.1 * v_5v;
@@ -229,9 +229,9 @@ void main_subtask_usb_extra_device(void)
 {
     static uint64_t next_usb_checkup = 0;
 
-    if (CLK_get_ms() > next_usb_checkup)
+    if (timer_read64() > next_usb_checkup)
     {
-        next_usb_checkup = CLK_get_ms() + 10;
+        next_usb_checkup = timer_read64() + 10;
 
         USB_HandleExtraDevice();
     }
@@ -325,9 +325,9 @@ int main(void)
         keyboard_task();
 
 #ifdef CONSOLE_ENABLE
-        if (CLK_get_ms() > next_print)
+        if (timer_read64() > next_print)
         {
-            next_print = CLK_get_ms() + 250;
+            next_print = timer_read64() + 250;
             //Add any debug information here that you want to see very often
             //dprintf("5v=%u 5vu=%u dlow=%u dhi=%u gca=%u gcd=%u\r\n", v_5v, v_5v_avg, v_5v_avg - V5_LOW, v_5v_avg - V5_HIGH, gcr_actual, gcr_desired);
         }
diff --git a/tmk_core/protocol/arm_atsam/usb/udi_cdc.c b/tmk_core/protocol/arm_atsam/usb/udi_cdc.c
index 5f3c289e8..ffe3526db 100644
--- a/tmk_core/protocol/arm_atsam/usb/udi_cdc.c
+++ b/tmk_core/protocol/arm_atsam/usb/udi_cdc.c
@@ -1227,9 +1227,9 @@ uint32_t cdc_tx_send_time_next;
 
 void CDC_send(void)
 {
-    while (CLK_get_ms() < cdc_tx_send_time_next);
+    while (timer_read64() < cdc_tx_send_time_next);
     udi_cdc_tx_send(0);
-    cdc_tx_send_time_next = CLK_get_ms() + CDC_SEND_INTERVAL;
+    cdc_tx_send_time_next = timer_read64() + CDC_SEND_INTERVAL;
 }
 
 uint32_t CDC_print(char *printbuf)
@@ -1238,7 +1238,7 @@ uint32_t CDC_print(char *printbuf)
     char *buf = printbuf;
     char c;
 
-    if (CLK_get_ms() < 5000) return 0;
+    if (timer_read64() < 5000) return 0;
 
     while ((c = *buf++) != 0 && !(count >= MAX_PRINT))
     {
@@ -1339,7 +1339,7 @@ void CDC_init(void)
     inbuf.count = 0;
     inbuf.lastcount = 0;
     printbuf[0] = 0;
-    cdc_tx_send_time_next = CLK_get_ms() + CDC_SEND_INTERVAL;
+    cdc_tx_send_time_next = timer_read64() + CDC_SEND_INTERVAL;
 }
 
 #else //CDC line 62
diff --git a/tmk_core/protocol/arm_atsam/usb/usb2422.c b/tmk_core/protocol/arm_atsam/usb/usb2422.c
index ac19bf4ea..d6e192242 100644
--- a/tmk_core/protocol/arm_atsam/usb/usb2422.c
+++ b/tmk_core/protocol/arm_atsam/usb/usb2422.c
@@ -64,7 +64,7 @@ void USB_write2422_block(void)
         i2c0_transmit(USB2422_ADDR, dest, 34, 50000);
         SERCOM0->I2CM.CTRLB.bit.CMD = 0x03;
         while (SERCOM0->I2CM.SYNCBUSY.bit.SYSOP) { DBGC(DC_USB_WRITE2422_BLOCK_SYNC_SYSOP); }
-        CLK_delay_us(100);
+        wait_us(100);
     }
 
     DBGC(DC_USB_WRITE2422_BLOCK_COMPLETE);
@@ -135,7 +135,7 @@ void USB2422_init(void)
     sr_exp_data.bit.HUB_RESET_N = 1; //reset high
     SR_EXP_WriteData();
 
-    CLK_delay_us(100);
+    wait_us(100);
 
 #ifndef MD_BOOTLOADER
 
@@ -154,10 +154,9 @@ void USB_reset(void)
     //pulse reset for at least 1 usec
     sr_exp_data.bit.HUB_RESET_N = 0; //reset low
     SR_EXP_WriteData();
-    CLK_delay_us(1);
+    wait_us(2);
     sr_exp_data.bit.HUB_RESET_N = 1; //reset high to run
     SR_EXP_WriteData();
-    CLK_delay_us(1);
 
     DBGC(DC_USB_RESET_COMPLETE);
 }
@@ -247,7 +246,7 @@ void USB_set_host_by_voltage(void)
 
     SR_EXP_WriteData();
 
-    CLK_delay_ms(250);
+    wait_ms(250);
 
     while ((v_5v = adc_get(ADC_5V)) < ADC_5V_START_LEVEL) { DBGC(DC_USB_SET_HOST_5V_LOW_WAITING); }
 
@@ -313,11 +312,11 @@ uint8_t USB2422_Port_Detect_Init(void)
 
     USB_set_host_by_voltage();
 
-    port_detect_retry_ms = CLK_get_ms() + PORT_DETECT_RETRY_INTERVAL;
+    port_detect_retry_ms = timer_read64() + PORT_DETECT_RETRY_INTERVAL;
 
     while (!USB_active())
     {
-        tmod = CLK_get_ms() % PORT_DETECT_RETRY_INTERVAL;
+        tmod = timer_read64() % PORT_DETECT_RETRY_INTERVAL;
 
         if (v_con_1 > v_con_2) //Values updated from USB_set_host_by_voltage();
         {
@@ -333,7 +332,7 @@ uint8_t USB2422_Port_Detect_Init(void)
             else { DBG_LED_OFF; }
         }
 
-        if (CLK_get_ms() > port_detect_retry_ms)
+        if (timer_read64() > port_detect_retry_ms)
         {
             DBGC(DC_PORT_DETECT_INIT_FAILED);
             return 0;