# lv_tick.h (/api/tick/lv_tick_h)
Provide access to the system tick with 1 millisecond resolution
Functions [#functions]
lv_delay_set_cb [#lv_delay_set_cb]
Set a callback for a blocking delay
```c title=" " lineNumbers=1
void lv_delay_set_cb(lv_delay_cb_t cb)
```
Parameters
| Name | Type | Description |
| ---- | -------------------------------- | --------------------- |
| `cb` | | pointer to a callback |
lv_tick_set_cb [#lv_tick_set_cb]
Set the custom callback for 'lv\_tick\_get'
```c title=" " lineNumbers=1
void lv_tick_set_cb(lv_tick_get_cb_t cb)
```
Parameters
| Name | Type | Description |
| ---- | ----------------------------------- | ------------------------------------- |
| `cb` | | call this callback on 'lv\_tick\_get' |
lv_tick_get [#lv_tick_get]
Get the elapsed milliseconds since start up
```c title=" " lineNumbers=1
uint32_t lv_tick_get(void)
```
**Returns:** — the elapsed milliseconds
lv_tick_get_cb [#lv_tick_get_cb]
Get the custom callback for 'lv\_tick\_get'
```c title=" " lineNumbers=1
lv_tick_get_cb_t lv_tick_get_cb(void)
```
**Returns:** — call this callback on 'lv\_tick\_get'
lv_tick_inc [#lv_tick_inc]
You have to call this function periodically. It is typically safe to call from an interrupt handler or a different thread.
```c title=" " lineNumbers=1
void lv_tick_inc(uint32_t tick_period)
```
Parameters
| Name | Type | Description |
| ------------- | --------------------------- | ------------------------------------------------ |
| `tick_period` | | the call period of this function in milliseconds |
lv_tick_elaps [#lv_tick_elaps]
Get the elapsed milliseconds since a previous time stamp
```c title=" " lineNumbers=1
uint32_t lv_tick_elaps(uint32_t prev_tick)
```
Parameters
| Name | Type | Description |
| ----------- | --------------------------- | ----------------------------------------------------------------------------------------------- |
| `prev_tick` | | a previous time stamp (return value of ) |
**Returns:** — the elapsed milliseconds since 'prev\_tick'
lv_tick_diff [#lv_tick_diff]
Get the elapsed milliseconds between two time stamps
```c title=" " lineNumbers=1
uint32_t lv_tick_diff(uint32_t tick, uint32_t prev_tick)
```
Parameters
| Name | Type | Description |
| ----------- | --------------------------- | -------------------------- |
| `tick` | | a time stamp |
| `prev_tick` | | a time stamp before `tick` |
**Returns:** — the elapsed milliseconds between `prev_tick` and `tick`
lv_delay_ms [#lv_delay_ms]
Delay for the given milliseconds. By default it's a blocking delay, but with a custom delay function can be set too
```c title=" " lineNumbers=1
void lv_delay_ms(uint32_t ms)
```
Parameters
| Name | Type | Description |
| ---- | --------------------------- | ----------------------------------- |
| `ms` | | the number of milliseconds to delay |
Typedefs [#typedefs]
lv_tick_get_cb_t [#lv_tick_get_cb_t]
```c title=" " lineNumbers=1
typedef uint32_t(* lv_tick_get_cb_t) (void)
```
* `lv_tick_set_cb` — param `cb`
lv_delay_cb_t [#lv_delay_cb_t]
```c title=" " lineNumbers=1
typedef void(* lv_delay_cb_t) (uint32_t ms)
```
* `lv_delay_set_cb` — param `cb`
Dependencies [#dependencies]