diff --git a/boards/mulle/board.c b/boards/mulle/board.c
index 50df907e80..6774901cb6 100644
--- a/boards/mulle/board.c
+++ b/boards/mulle/board.c
@@ -28,7 +28,8 @@
 #include "periph/spi.h"
 #include "nvram-spi.h"
 #include "nvram.h"
-#include "xtimer.h"
+#include "ztimer.h"
+#include "timex.h"
 #include "vfs.h"
 #include "fs/devfs.h"
 #include "mtd_spi_nor.h"
@@ -115,7 +116,7 @@ void board_init(void)
 
 
     /* NVRAM requires xtimer for timing */
-    xtimer_init();
+    ztimer_init();
 
     /* Initialize NVRAM */
     status = mulle_nvram_init();
diff --git a/drivers/nvram_spi/Kconfig b/drivers/nvram_spi/Kconfig
index 49aa0041de..9d0af2163a 100644
--- a/drivers/nvram_spi/Kconfig
+++ b/drivers/nvram_spi/Kconfig
@@ -11,4 +11,4 @@ config MODULE_NVRAM_SPI
     depends on TEST_KCONFIG
     select MODULE_NVRAM
     select MODULE_PERIPH_SPI
-    select MODULE_XTIMER
+    select ZTIMER_USEC
diff --git a/drivers/nvram_spi/Makefile.dep b/drivers/nvram_spi/Makefile.dep
index dc07832471..2e7594ee97 100644
--- a/drivers/nvram_spi/Makefile.dep
+++ b/drivers/nvram_spi/Makefile.dep
@@ -1,3 +1,3 @@
 FEATURES_REQUIRED += periph_spi
 USEMODULE += nvram
-USEMODULE += xtimer
+USEMODULE += ztimer_usec
diff --git a/drivers/nvram_spi/nvram-spi.c b/drivers/nvram_spi/nvram-spi.c
index 3ecd0a18d6..9f82077b09 100644
--- a/drivers/nvram_spi/nvram-spi.c
+++ b/drivers/nvram_spi/nvram-spi.c
@@ -14,7 +14,7 @@
 #include "byteorder.h"
 #include "periph/spi.h"
 #include "periph/gpio.h"
-#include "xtimer.h"
+#include "ztimer.h"
 
 /**
  * @ingroup     drivers_nvram
@@ -42,7 +42,7 @@ typedef enum {
 
 /** @brief Delay to wait between toggling CS pin, on most chips this can probably be
  * removed. */
-#define NVRAM_SPI_CS_TOGGLE_TICKS xtimer_ticks_from_usec(1)
+#define NVRAM_SPI_CS_TOGGLE_US      1
 
 /**
  * @brief Copy data from system memory to NVRAM.
@@ -140,7 +140,7 @@ static int nvram_spi_write(nvram_t *dev, const uint8_t *src, uint32_t dst, size_
     /* Enable writes */
     spi_transfer_byte(spi_dev->spi, spi_dev->cs, false, NVRAM_SPI_CMD_WREN);
     /* Make sure we have a minimum gap between transfers */
-    xtimer_spin(NVRAM_SPI_CS_TOGGLE_TICKS);
+    ztimer_spin(ZTIMER_USEC, NVRAM_SPI_CS_TOGGLE_US);
     /* Write command and address */
     spi_transfer_byte(spi_dev->spi, spi_dev->cs, true, NVRAM_SPI_CMD_WRITE);
     spi_transfer_bytes(spi_dev->spi, spi_dev->cs, true,
@@ -200,7 +200,7 @@ static int nvram_spi_write_9bit_addr(nvram_t *dev, const uint8_t *src, uint32_t
     /* Enable writes */
     spi_transfer_byte(spi_dev->spi, spi_dev->cs, false, NVRAM_SPI_CMD_WREN);
     /* Insert needed delay between transactions */
-    xtimer_spin(NVRAM_SPI_CS_TOGGLE_TICKS);
+    ztimer_spin(ZTIMER_USEC, NVRAM_SPI_CS_TOGGLE_US);
     /* Write command and address */
     spi_transfer_byte(spi_dev->spi, spi_dev->cs, true, cmd);
     spi_transfer_byte(spi_dev->spi, spi_dev->cs, true, addr);
diff --git a/tests/driver_nvram_spi/Makefile b/tests/driver_nvram_spi/Makefile
index d056bae463..8b485a5cc9 100644
--- a/tests/driver_nvram_spi/Makefile
+++ b/tests/driver_nvram_spi/Makefile
@@ -1,7 +1,7 @@
 include ../Makefile.tests_common
 
 USEMODULE += nvram_spi
-USEMODULE += xtimer
+USEMODULE += ztimer_usec
 
 # set default device parameters in case they are undefined
 TEST_NVRAM_SPI_DEV           ?= SPI_DEV\(0\)
diff --git a/tests/driver_nvram_spi/app.config.test b/tests/driver_nvram_spi/app.config.test
index a56d76d65f..68e9fc72c0 100644
--- a/tests/driver_nvram_spi/app.config.test
+++ b/tests/driver_nvram_spi/app.config.test
@@ -1,4 +1,4 @@
 # this file enables modules defined in Kconfig. Do not use this file for
 # application configuration. This is only needed during migration.
 CONFIG_MODULE_NVRAM_SPI=y
-CONFIG_MODULE_XTIMER=y
+CONFIG_ZTIMER_USEC=y
diff --git a/tests/driver_nvram_spi/main.c b/tests/driver_nvram_spi/main.c
index a517784068..46f70a6c9b 100644
--- a/tests/driver_nvram_spi/main.c
+++ b/tests/driver_nvram_spi/main.c
@@ -23,7 +23,8 @@
 #include <ctype.h>
 
 #include "board.h"
-#include "xtimer.h"
+#include "ztimer.h"
+#include "timex.h"
 #include "periph/spi.h"
 #include "nvram-spi.h"
 
@@ -137,7 +138,7 @@ int main(void)
     puts("!!! This test will erase everything on the NVRAM !!!");
     puts("!!! Unplug/reset/halt device now if this is not acceptable !!!");
     puts("Waiting for 10 seconds before continuing...");
-    xtimer_sleep(start_delay);
+    ztimer_sleep(ZTIMER_USEC, start_delay * US_PER_SEC);
 
     puts("Reading current memory contents...");
     for (i = 0; i < TEST_NVRAM_SPI_SIZE; ++i) {
diff --git a/tests/events/Makefile.board.dep b/tests/events/Makefile.board.dep
new file mode 100644
index 0000000000..76e7d4dd4a
--- /dev/null
+++ b/tests/events/Makefile.board.dep
@@ -0,0 +1,7 @@
+# mulle will always select ztimer through requiring nvram_spi module
+# because of order of inclusion 'make' depency resolution will still select
+# xtimer while 'Kconfig' wont, so early require 'ztimer_usec'
+# for 'make' to avoid this
+ifneq (,$(filter mulle,$(BOARD)))
+  USEMODULE += ztimer_usec
+endif