Timer2 Mode0

init
Timer initializaion functions
#define	timer2_mode0_12T_init()
	Initialize mode0 12T for timer2.
#define	timer2_mode0_1T_init()
	Initialize mode0 1T for timer2.

config
Timer configuration functions
#define	timer2_mode0_enable_P30_output()   (bit_set(INT_CLKO, SBIT2))
	Enable output of meander with timer times on P3.0 pin.
#define	timer2_mode0_disable_P30_output()   (bit_clr(INT_CLKO, CBIT2))
	Disable output of meander with timer times on P3.0 pin.
#define	is_timer2_mode0_P30_output_enabled()   (test_if_bit_set(INT_CLKO, SBIT2))

run in async mode
Timer run/stop/reload functions
#define	timer2_mode0_start(ticks)
	Run timer2 mode0 with interrupt support.
#define	timer2_mode0_direct_start(th0, tl0)
	Run timer2 mode0 with direct set of TH0 and TL0 registers.
#define	timer2_mode0_stop()
	Stop timer2 mode0.
#define	timer2_mode0_reload(ticks)
	Reload timer2 ticks on the fly.
#define	timer2_mode0_direct_reload(th2, tl2)
	Reload timer2 T2H and T2L registers on the fly.
#define	is_timer2_mode0_started()   (test_if_bit_set(AUXR, SBIT4))
	Get timer2 started status.

baud rate enable/disable
Select timer2 as UART1 baud rate generator
#define	timer2_mode0_enable_as_uart1_baud_rate()   (bit_set(AUXR, SBIT0))
	Select timer2 as uart1 baud rate generator.
#define	timer2_mode0_disable_as_uart1_baud_rate()   (bit_clr(AUXR, CBIT0))
	Unselect timer2 as uart1 baud rate generator.
#define	is_timer2_mode0_as_uart1_baud_rate_enabled()   (test_if_bit_set(AUXR, SBIT0))
	Is timer0 used as UART1 baud rate generator?

Detailed Description

Functions and data structures for timer2 mode0.

Timer can work as COUNTER or TIMER.

Counter increments on external singnal (like pin 1/0 change state).

8051 chips timer2

• mode0 - 16-Bit Auto-Reload Timer/Counter

For timer:

• Input of timer is system clock.
• By default timer input is 12T mode. Timer increments by sysClock/12.
• Timer input can be switched to 1T mode. In this mode timer increments by sysClock/1.

Timer2 mode0 can be used in sync (main prorgam flow blocked until timer overloaded) and interrupt (call interrupt handler on timer overloaded) modes.

Author

Michael Golovanov

Macro Definition Documentation

is_timer2_mode0_as_uart1_baud_rate_enabled

#define is_timer2_mode0_as_uart1_baud_rate_enabled

(

)

(test_if_bit_set(AUXR, SBIT0))

Is timer0 used as UART1 baud rate generator?

by default timer0 used as UART1 baud rate generator

Returns

bool true if timer0 used as UART1 baud rate generator, otherwise false

is_timer2_mode0_P30_output_enabled

#define is_timer2_mode0_P30_output_enabled

(

)

(test_if_bit_set(INT_CLKO, SBIT2))

Get output to pin P3.0 output flag enabled value

Returns

bool true if output enabled oterwise false

is_timer2_mode0_started

#define is_timer2_mode0_started

(

)

(test_if_bit_set(AUXR, SBIT4))

Get timer2 started status.

Returns

bool true if started otherwise false

timer2_mode0_12T_init

#define timer2_mode0_12T_init

(

)

Value:

do {                                                                    \
    enable_mcu_interrupts();                                            \
    enable_timer2_interrupt();                                          \
    AUXR &= 0xE2;                                                       \
} while(0)

Initialize mode0 12T for timer2.

Timer2 could be used for UART. This method init timer2 as general purpose timer in mode0 with input from sysClk/12. Using timer2 in this mode disable UART capability.

timer2_mode0_1T_init

#define timer2_mode0_1T_init

(

)

Value:

do {                                                                    \
    enable_mcu_interrupts();                                            \
    enable_timer2_interrupt();                                          \
    AUXR &= 0xE2;                                                       \
    AUXR |= 0x05;                                                       \
} while(0)

Initialize mode0 1T for timer2.

Timer2 could be used for UART. This method init timer2 as general purpose timer in mode0 with input from sysClk/1. Using timer2 in this mode disable UART capability.

timer2_mode0_direct_reload

#define timer2_mode0_direct_reload	(		th2,
			tl2
	)

Value:

do {                                                            \
    T2H = th2;                                                  \
    T2L = tl2;                                                  \
} while(0)

Reload timer2 T2H and T2L registers on the fly.

Reload is available in mode 0 only

Parameters

th2	uint8_t T2H value
tl2	uint8_t T2L value

timer2_mode0_direct_start

#define timer2_mode0_direct_start	(		th0,
			tl0
	)

Value:

do {                                                        \
    timer2_mode0_direct_reload(th0, tl0);                   \
                                                            \
    bit_set(AUXR, SBIT4);                                   \
} while(0)

Run timer2 mode0 with direct set of TH0 and TL0 registers.

Before run timer2_mode0_12T_init or timer2_mode0_1T_init should be called.

After run program flow not blocked and interrupt will raised when timer is overloaded. Interrupt handler void timer2ISR(void) __interrupt(12) should be defined in user code.

Timer rerun occurs after overloading and interuppt handler calling. Timer overloading occurs when [TH0, TL0] = 0xff + 1

Parameters

th0	uint8_t TH0 value
tl0	uint8_t TL0 value

timer2_mode0_disable_as_uart1_baud_rate

#define timer2_mode0_disable_as_uart1_baud_rate

(

)

(bit_clr(AUXR, CBIT0))

Unselect timer2 as uart1 baud rate generator.

by default timer0 used as UART1 baud rate generator

timer2_mode0_enable_as_uart1_baud_rate

#define timer2_mode0_enable_as_uart1_baud_rate

(

)

(bit_set(AUXR, SBIT0))

Select timer2 as uart1 baud rate generator.

by default timer0 used as UART1 baud rate generator

timer2_mode0_enable_P30_output

#define timer2_mode0_enable_P30_output

(

)

(bit_set(INT_CLKO, SBIT2))

Enable output of meander with timer times on P3.0 pin.

By default output is disabled

timer2_mode0_reload

#define timer2_mode0_reload

(

ticks

)

Value:

do {                                                            \
    uint16_t value = 0xffff - ticks;                            \
    T2L = value & 0xff;                                         \
    T2H = (value >> 8) & 0xff;                                  \
} while(0)

Reload timer2 ticks on the fly.

Reload is available in mode 0 only

Parameters

ticks

uint16_t timer ticks reloaded value

timer2_mode0_start

#define timer2_mode0_start

(

ticks

)

Value:

do {                                                        \
    timer2_mode0_reload(ticks);                             \
                                                            \
    bit_set(AUXR, SBIT4);                                   \
} while(0)

Run timer2 mode0 with interrupt support.

Before run timer2_mode0_12T_init or timer2_mode0_1T_init should be called.

After run program flow not blocked and interrupt will raised when timer is overloaded.

Interrupt handler void timer2ISR(void) __interrupt(12) should be defined in user code.

Timer rerun occurs after overloading and interuppt handler calling.

Parameters

ticks

uint16_t timer tick count

timer2_mode0_stop

#define timer2_mode0_stop

(

)

Value:

    {                               \
    bit_clr(AUXR, CBIT4); /* clear T2 run flag */           \
}

Stop timer2 mode0.

Before stop timer2_mode0_start should be called.