Built-in Routines

The mikroC PRO for 8051 compiler provides a set of useful built-in utility functions.

The Lo, Hi, Higher, Highest routines are implemented as macros. If you want to use these functions you must include built_in.h header file (located in the inlclude folder of the compiler) into your project.

The Delay_us and Delay_ms routines are implemented as “inline”; i.e. code is generated in the place of a call, so the call doesn’t count against the nested call limit.

The Vdelay_ms, Delay_Cyc and Get_Fosc_kHz are actual C routines. Their sources can be found in Delays.c file located in the uses folder of the compiler.

Lo
Hi
Higher
Highest

Delay_us
Delay_ms
Vdelay_ms
Delay_Cyc

Clock_kHz
Clock_MHz
Get_Fosc_kHz

Lo

Prototype	unsigned short Lo(long number);
Returns	Lowest 8 bits (byte)of `number`, bits `7..0`.
Description	Function returns the lowest byte of `number`. Function does not interpret bit patterns of `number` – it merely returns 8 bits as found in register. This is an “inline” routine; code is generated in the place of the call, so the call doesn’t count against the nested call limit.
Requires	Arguments must be variable of scalar type (i.e. Arithmetic Types and Pointers).
Example	d = 0x1AC30F4; tmp = Lo(d); // Equals 0xF4

Hi

Prototype	unsigned short Hi(long number);
Returns	Returns next to the lowest byte of `number`, bits 8..15.
Description	Function returns next to the lowest byte of `number`. Function does not interpret bit patterns of `number` – it merely returns 8 bits as found in register. This is an “inline” routine; code is generated in the place of the call, so the call doesn’t count against the nested call limit.
Requires	Arguments must be variable of scalar type (i.e. Arithmetic Types and Pointers).
Example	d = 0x1AC30F4; tmp = Hi(d); // Equals 0x30

Higher

Prototype	unsigned short Higher(long number);
Returns	Returns next to the highest byte of `number`, bits 16..23.
Description	Function returns next to the highest byte of `number`. Function does not interpret bit patterns of `number` – it merely returns 8 bits as found in register. This is an “inline” routine; code is generated in the place of the call, so the call doesn’t count against the nested call limit.
Requires	Arguments must be variable of scalar type (i.e. Arithmetic Types and Pointers).
Example	d = 0x1AC30F4; tmp = Higher(d); // Equals 0xAC

Highest

Prototype	unsigned short Highest(long number);
Returns	Returns the highest byte of `number`, bits 24..31.
Description	Function returns the highest byte of `number`. Function does not interpret bit patterns of `number` – it merely returns 8 bits as found in register. This is an “inline” routine; code is generated in the place of the call, so the call doesn’t count against the nested call limit.
Requires	Arguments must be variable of scalar type (i.e. Arithmetic Types and Pointers).
Example	d = 0x1AC30F4; tmp = Highest(d); // Equals 0x01

Delay_us

Prototype	void Delay_us(const unsigned long time_in_us);
Returns	Nothing.
Description	Creates a software delay in duration of `time_in_us` microseconds (a constant). Range of applicable constants depends on the oscillator frequency. This is an “inline” routine; code is generated in the place of the call, so the call doesn’t count against the nested call limit.
Requires	Nothing.
Example	Delay_us(1000); / One millisecond pause /

Delay_ms

Prototype	void Delay_ms(const unsigned long time_in_ms);
Returns	Nothing.
Description	Creates a software delay in duration of `time_in_ms` milliseconds (a constant). Range of applicable constants depends on the oscillator frequency. This is an “inline” routine; code is generated in the place of the call, so the call doesn’t count against the nested call limit.
Requires	Nothing.
Example	Delay_ms(1000); / One second pause /

Vdelay_ms

Prototype	void Vdelay_ms(unsigned time_in_ms);
Returns	Nothing.
Description	Creates a software delay in duration of `time_in_ms` milliseconds (a variable). Generated delay is not as precise as the delay created by Delay_ms. Note that `Vdelay_ms` is library function rather than a built-in routine; it is presented in this topic for the sake of convenience.
Requires	Nothing.
Example	pause = 1000; // ... Vdelay_ms(pause); // ~ one second pause

Delay_Cyc

Prototype	void Delay_Cyc(char Cycles_div_by_10);
Returns	Nothing.
Description	Creates a delay based on MCU clock. Delay lasts for 10 times the input parameter in MCU cycles. Note that `Delay_Cyc` is library function rather than a built-in routine; it is presented in this topic for the sake of convenience. There are limitations for `Cycles_div_by_10` value. Value `Cycles_div_by_10` must be between 2 and 257.
Requires	Nothing.
Example	Delay_Cyc(10); / Hundred MCU cycles pause /

Clock_kHz

Prototype	unsigned Clock_kHz(void);
Returns	Device clock in kHz, rounded to the nearest integer.
Description	Function returns device clock in kHz, rounded to the nearest integer. This is an “inline” routine; code is generated in the place of the call, so the call doesn’t count against the nested call limit.
Requires	Nothing.
Example	clk = Clock_kHz();

Clock_MHz

Prototype	unsigned short Clock_MHz(void);
Returns	Device clock in MHz, rounded to the nearest integer.
Description	Function returns device clock in MHz, rounded to the nearest integer. This is an “inline” routine; code is generated in the place of the call, so the call doesn’t count against the nested call limit.
Requires	Nothing.
Example	clk = Clock_MHz();

Get_Fosc_kHz

Prototype	unsigned long Get_Fosc_kHz(void);
Returns	Device clock in kHz, rounded to the nearest integer.
Description	Function returns device clock in kHz, rounded to the nearest integer. Note that `Get_Fosc_kHz` is library function rather than a built-in routine; it is presented in this topic for the sake of convenience.
Requires	Nothing.
Example	clk = Get_Fosc_kHz();

Want more examples and libraries?
Find them on